Glossary of Common Avian Medical Terms by Jeannine Miesle

Main Article: Avian Medical Terms / Bird Health & Diseases by Jeannine Miesle, MA, Allied Member, Association of Avian Veterinarians

Images:   Relevant Avian Anatomy Image Gallery 

Commonly Used Avian Medical Terms

Abdomen/Abdominal region:  between the thorax and pelvis: ventral part of bird, between vent and posterior sternum; flight muscles located between belly and breast

Abdominocentesis: drawing out fluid from abdominal cavity

Absess: localized accumulation of puss; associated with infection

Acanthosis: benign overgrowth of prickle-cell layer of skin; increased thickness of stratus spinosum (layer of epidermis containing prickle cells, also called spinosa layer and prickle cell layer), due to hypertrophy of cells

Accipiter: a certain group of hawks, including Sharp-shinned, Cooper’s and Northern Goshawk

ACE inhibitor: Angliotensin-converting enzyme; decreases function of this enzyme. Dilates blood vessels.

Acetabulum: hipbone socket that receives head of femur. The cup-shaped cavity at the base of the hipbone into which the ballshaped head of the femur fits.

Achromatosis: failure to lay down normal feather pigment

Acid: fluid containing high proportion of hydrogen ions, gives fluid sour taste; measured by pH units, 2 the most acid, 14 the least, chemical reactions in body take place at/near neutrality

ACTH: Adrenocorticotropic hormone secreted by pituitary gland which stimulates the adrenal gland to work

Acinar holocrine sebaceous glands: smallest secreting portion of the gland, releases the secretion, sebum. Small glands that release sebum, e.g., uropygial gland

Acinetobacter: a gram neg. pathogen bacteria; a milder pathogen

Acquired disease: caused by disorder, injury, tumor

Activated charcoal: treated to increase adsorptive power (ability to have chemicals adhere to it), used to treat poisoning

Active immunity: produced when immune system reacts to a stimulus (virus or bacteria) and produces antibodies and cells which protect it from the disease

Acuminate: abruptly narrow to sharp point

Acute: sharp, severe, sudden, rapid onset, short-course symptoms

Adenitis: gland inflammation

Adenocarcinoma: malignant tumor or gland-like structure arising from secretory epithelium 

Adenoma: benign epithelial tumor composed of cells from glandular epithelium

Adenovirus: causes hepatitis in birds

Adhesion: band of fibers that hold structures together in abnormal way

Adipose: fatty tissue, cells that store fat

Adjuvant: substance added to killed vaccines to stimulate stronger or faster immune response by body; common ones contain aluminum compounds, drugs or chemo/radiation therapy; supplemental treatment

Adrenal cortex: large, outer, firm layer of adrenal gland

Adrenal glands: 2 small glands near kidneys, produce hormones

Adrenaline: hormone produced by adrenal glands, elevates heart and respiration rates, aka epinephrine

Adsorb/Adsorbent: solid substance which attracts other molecules to its surface

Aerobe/Aerobic bacteria: organism that lives only in presence of oxygen

Anaerobic grows in absence of oxygen

Aeromonas: gram-negative, anaerobic, rod-shaped bacteria, grows in water and soil, aerobic,

Aerophagia: gulping air, spasmodic swallowing of air, nervousness and anxiety, gas in intestinal tract

Aerosol: system in which solid or liquid particles are suspended in air or other gas

Afferent and Efferent nervous system: sends impulses or signals to and from the brain/central nervous system

Aflatoxins: toxic compound composed of molds, contaminates, in stored food, cases aspergillosis

Agenesis: absence of body part

Agglutination: sticking together of insoluble antigens such as bacteria, viruses, or erythrocytes by an antibody. Agg. Assays used to type human blood before transfusion

Agonist: second drug which stops action of the first drug; drug which has physiological effect; has an affinity to a cellular receptor; binds to a cellular receptor for another drug without producing any physiological effects itself

Airfoil: special shape of birds’ wings, produces lifting effect as it moves forward through air  

Airfoil Wing: shaped with curve on top rather than beneath

Bird  Respiratory SystemAir sacs: thin-walled, membranous sacs of respiratory system, allows unidirectional flow of air into lungs and through body; 9 air sacs: 4 paired: 2 cervical, 2 anterior thoracic, 2 posterior thoracic, 2 abdominal and 1 unpaired interclavicular. Fill parts of body cavities and penetrate muscles and bones; interconnect with each other and lungs to form efficient one-way path for air movement during breathing; help remove waste heat generated during flight, not used to exchange oxygen and CO2

Air sac mites: small, dark mites in windpipe and air sacs, irritation leads to asphyxiation, wheezing, whistling in breathing, Ivermectin

Air space: pocket of air between the shell membranes at the large end of the egg; as the developing embryo uses water and additional water evaporates from the shell, air moves into the egg from outside, expanding the air space

Airie: A nest built on the wall or side of a cliff by a raptor

Alar Bar: A contrasting line running on the front edge of the mid-wing section to the bird’s body

Albino: (Leucistic) completely white animal, cannot make pigment, blue or pink eyes.  Please refer to Albino / Leucistic / Partial White / Pied Hummingbirds for photos and more information

Albinism: Occasional and erratic occurrence of white plumage, seen partial or complete in non-white plumage birds, caused by coloring deficiency in the feathers

Albumin: egg white, composed of water and protein; it is a protein in the blood responsible for maintenance of osmotic (water) pressure in the blood; attaches to large molecules in blood and transports them; produced by liver, aka serum albumin.

Alele form of gene; one of two or more alternative forms of a gene, occupying the same position locus on paired chromosomes and controlling the same inherited characteristic

Alimentary: food or digestive tract

Aliquots: sample

Alkaline: substance with few hydrogen ions, pH over 7, e.g., lye

Allantois: membranous sac that balloons off a bird embryo’s gut; solid wastes produced by the developing embryo that can’t be passed through the eggshell are diverted into the allantois

Allergen: causes allergic reaction

Allo: other, deviating from norm

Allo-feeding/preening: mutual behavior 

Allogenic: birds of same species but different genetic constitution (antigenetically distinct)

Allopatric: biologically related to or taking place in different areas, esp. in speciation in which isolated populations evolve into good species

Allopecia: feather loss; can be nutritional or behavioral; often an adrenal disease

Alternate plumage: breeding plumage, Usually the more colourful plumage seen on an individual adult bird during before and after nesting season, also known as alternate plumage.

Altricial: Condition describing certain young birds when hatched, that have no feathers, eyes are closed and totally dependent on their parents.

Alula BoneAlula: small joint on manus, like thumb, 3-4 quill-like feathers attached. Used for low-speed flight and maneuverability. Prevents stalling in flight. The feathers function like slats on planes by increasing the camber of the wing, helping bird to land and take off, supported by anterior-most digit

Alular quills: the three feathers attached to the alula originating from base of primaries; low- speed fight, landing, take-off; attached to the thumb or pollex, located midwing area.

Alular quill coverts: small feathers coving the quilt of each flight feather

Ambient: surrounding, as in air temperature

Amino Acids: any of large group of compounds containing amino and carboxyl group; building blocks of proteins; occur naturally in plants and animal tissue

Aminoglycoside: a class of antibiotics which acts by interfering with bacterial protein synthesis within the bacteria; results in death of the bacteria; Include gentamicin, kanamycin, neomycin, streptomycin, tobramycin, amikacin; many not well-absorbed by digestive system, so administered IM or topically

Amniotic A modern egg’s shell having a waterproof membrane

Amorphous: without form, shape or boundaries, not allowing clear classification or analysis, as in amorphous urates

Amylase: digestive enzyme, produced by pancreas; breaks down carbohydrates and starches; in saliva

Amyloid: containing/resembling a starch; abnormal proteins

Amyloidosis: malformed or abnormal amyloid proteins are deposited in organs or tissues and cause harm; amyloids build up in tissues either as a primary idiopathic disease or secondary chronic disease as in TB or osteomyelitis; results in cell toxicity and organ dysfunction

Amylum: chemical starch as in potato

Anabolic steroid: type of steroid which promotes tissue building, like muscle (not a corticosteroid like cortisone)

Anabolism: process which changes food into living tissue, e.g., bone growth; the constructive phase of metabolism in which body cells synthesize protoplasm for growth and repair

Anaerobic bacteria: live and grow in no or little oxygen, e.g., C. tetani (tetanus)

Anaerobe: organism that grows without oxygen; many harmless

Analgesic: pain-relieving drug

Anamnesis: history of bird and current illness; about caretaking, environment, husbandry, changes

Anamnestic response: faster or greater immune response produced by animal which had previously encountered that specific antigen. Memory cells are responsible for this quick response; aka “secondary response.”

Anaplasia: loss of differentiation of cells; irreversible alteration in adult cell toward more primitive cell types; a characteristic of tumor cells; change in the structure of cells and their orientation to each other.

Anastomosis: surgical union of parts, esp. hollow, tubular parts;

  1. communication between 2 organs or vessels by collateral channels
  2. surgical, traumatic, or pathological formation of an opening between two normally distinct spaces or structures; surgery: the surgical union of two hollow organs, e.g. blood vessels or parts of the intestine, to ensure continuity of the passageway
  3. intestinal establishment of a connector between 2 distinct parts of the intestines
  4. natural joint: the connection or place of connection of two or more parts of a natural branching system, e.g. of blood vessels, leaf veins, stems of woody plants, or rivers

Androgen: hormone producing male sex characteristics; e.g., testosterone

Androstenedione: steroid produced by testes, adrenal cortex, and ovaries; immunization against it increases fertility

Anechoic: unable to move, faint, feel, respond, exhausted, in ultrasonography, the absence of internal echoes

Anemia: a decrease in number of circulating erythrocytes, below normal amount of hemoglobin in RBC, or combination of both; causes weakness and debilitation; caused by blood loss, decreased RBC production, increased RBC destruction; caused by blood trauma and GI bleeding, hemorrhage, ulcers, liver disease, GI foreign bodies;

Anesthesia: loss of sensation or feeling induced by drugs

Angiography: x-ray of vessels after injecting contrasting fluid

Angiotensin-converting-enzyme inhibitor (ACE inhibitor): drug which decreases the function of this enzyme; angiotensin is a blood vessel constrictor, so ACE inhibitors dilate blood vessels

Anhedral Downward curve of a bird’s wing in flight. E.g.,. Turkey Vulture.

Anisocoria: pupils of eyes not equal size (refer to Wing Anatomy)

Anisocytosis: abnormal size variation in erythrocytes

Anisodactile: 3 toes in front, one behind, as in perching wild birds

Ankylosis: abnormal immobility and consolidation of joint; caused by destruction of membranes that line the joint or faulty bone structure or arthritis; joint assumes least painful position and remains fixed in it, sometimes permanently

Annular: ring-shaped, circular, as in inflammation and crusting in dermatitis or ringworm

Anorexia: loss of appetite

Antebrachium: the forearm area, supported by the radius and ulna

Anthelmintic: substance that destroys parasitic worms (intestinal helminthes)

Anthracosis: benign deposits of coal dust in lungs

Anthropomorphism: interpreting behavior of animals in terms of human feelings, motivations or characteristics

Antibiogram: antibiotic sensitivity test

Antibiotic: natural or synthetic chemical substance that kills microorganism or inhibits their growth; treats bacterial infections; Broad-spectrum antibiotic treats wide variety of bacteria (e.g., penicillin, tetracycline, erythromycin); Some treat specific groups, like Gram positive and Gram neg. some kill and some prevent bacteria from reproducing (bactericidal and bacteriostatic)

Antibiotic beads: combat musculoskeletal infections; lined with tobramycin powder

Antibody: specialized protein contained in the blood serum and formed by the b-lymphocyte white blood cell; responds to an antigen to which animal has been exposed; antibody destroys or inactivates certain foreign substances in body, especially microbes; produced by immune system as protection against infection and disease

Antisense: having a strand of DNA complementary to other genetic material so that expression of a trait can be regulated.

Antiseptic: acts against sepsis (toxins in blood); formulated for use on living tissue to prevent or inhibit growth/action of organisms

Antiserum: blood serum from animal after immunization with particular antigen; contains antibodies specific for that antigen as well as other antigens with which the animal has previously been immunized.

Antispasmodic: relieves or decreases muscle spasms; includes smooth muscles (muscle in intestines that causes them to contract and move food through digestive system)

Antitoxin: an antibody with the ability to neutralize a specific toxin.

Antitussive: cough suppressant

Anular pad: ring-shaped vessel in eye

Anuria: kidney failure, no urine produced

Aortic arch: curvature of aorta where it turns from its cranial path to a caudal one and becomes the thoracic aorta

Apex: narrow tip of heart at distal end

Aplasia: lack of development of an, tissue, or cell

Aplastic anemia: erythrocytes, leukocytes and platelets not produced in sufficient numbers

Apnea: absence of breathing

Aponeurosis: broad, sheet-like tendon

Apoptosis: programmed cell destruction

Appositional: placed in proximity

Apterium/Apteria: bare, unfeathered areas between feather tracts

Aqueous humor: fluid in eyeball, provides nourishment to interior eye, keeps eyeball inflated

Arboreal A tree dwelling bird

Archaeopteryx First fossilized bird known to exist.

Aerial insectivores: Bird species who feed on insects while flying

Arrhenoblastoma: ovarian stromal tumor

Arrhythmia: variation from normal heart rhythm

Arteries: thick-walled vessels that carry blood away from heart to lungs and body tissues; pulmonary arteries carry deoxygenated blood to lungs, but all other arteries carry oxygenated blood; have muscular walls to allow contraction and expansion to move blood throughout the body

Arthritis: inflammation and swelling of joints

Arthrodesis: aka artificial ankylosis or syndesis; artificial induction of joint ossification between two bones via surgery

Arthrocentesis; puncture into a joint to remove fluid

Articular/Articulated: pertaining to a joint, having a joint, an artificial appendage, limb, joints composed of segments

Articulating: the site of junction or union between bones, especially one that allows free motion of the bones

Artifact: anything not naturally present but introduced by some external source; artificial, manmade product; produced by an external agent or action, such as a structure seen in a microscopic specimen after fixation that is not present in a living tissue; in biochemical blood analysis, some abnormal results are due to disease; those that aren’t related to disease are artifacts. E.g., physiological changes, clinical condition of patient, blood collection method, storage and transport of sample

Artifactual hymolysis: breakdown of red blood cells due to human manipulation

Arytenoid cartilage: one of the paired laryngeal cartilages in the dorsal part of the larynx that provides attachment for the muscles that adduct or abduct the vocal folds.

Ascarids: intestinal parasite, roundworms

Ascites: accumulation of fluid in peritoneal cavity (es-site-eeze)

Ascomycetes: class of fungi containing true yeasts and dermatophytes (skin parasites)

Asepsis: condition in which living pathogenic organisms are absent

Aspergilloma: tumor-like granulomatous mass formed by colonization of aspergillus in the respiratory organs, may disseminate through bloodstream to brain, heart, kidneys

Aspergillosis: fungal infection in respiratory system

Aspergillus fumigatus: causes Aspergillosis; fungus, including molds, caused by dampness

Aspirate: to withdraw fluid from a body cavity using an aspirator or suction syringe, as in withdrawal of blood sample with syringe and needle; to inhale a fluid or foreign body into the bronchi and lungs, often after vomiting

Assay: qualitative or quantitative analysis of a substance, esp drug

Assimilation: conversion of nutritive material into living tissue; anabolism

Asymptomatic: without symptoms but carrying or shedding disease organisms

Asynchronous hatching: single clutch hatches over a period of several days; incubation begins when first egg is laid; Synchronous is all hatch at same time.

Ataxia: loss of coordination in the muscles, esp the extremities, results in staggering gate

Atelectasis: collapsed or airless lung

Atherosclerosis/arteriosclerosis: hardening and narrowing of arteries; causes heart attacks, strokes, peripheral vascular disease; fat and cholesterol plaques form in the intima of arteries; Vascular intima is the innermost coat of a blood vessel.

Atonic: lack of muscle tone

Anopy: hypersensitivity: an allergy with symptoms produced upon exposure to an antigen; inhalant allergies, e.g., pollen or dust

Atoxoplasma: liver enlarged, dark area under skin of abdomen, bloody diarrhea, weight loss, dehydrated, depression, sudden death, “Black spot.”

Atresea/altresic (choanal): the congenital absence of or pathological closure of an opening, passage, or cavity; occlusion or absence of a normal body opening or tubular organ

Atrial fibrillation: atria (chambers of heart that receive blood) contract rapidly, irregularly and independently of the ventricles (chambers that pump the blood). Decreases the efficiency of the heart and its ability to move blood.

Atrial flutter: atria contracts rapidly, irregularly, and independently of the ventricles; this decreases the efficiency of the heart and its ability to move blood.

Atrium/atria: two chambers of the heart that receive blood; right atrium receives blood from body, left receives oxygenated blood from lungs

Atrophic rhinitis inflammation of nose and mucous membranes resulting in degeneration of tissue from nerve damage

Atropine: smooth muscle relaxant, pre-anesthetic

Atrophy: decrease in size or complete wasting of organ, tissue, muscle, cell; suggests reduced innervation

Attenuated: Weakened; an attenuated virus is one that has been changed and will no longer cause disease; used in modified live vaccines

Auditory meatus: ear opening

Auricula: ear area

Auricular coverts/feathers: earpatch, soft, loosely-webbed feathers on side of head to protect ear; overlap the ear, called coverts; no external pinna but have slight thickening of skin around ear

Auscultation: listening through stethoscope to body sounds for diagnosis

Autocthonos flora; normal gut flora, takes 3-4 weeks to develop in chick

Autochthonus: found in original locality; as in disease, found in original place

Autogenous: self-produced, selfgenerated; substances generated in the body

Autogenous vaccine: suspension make from material obtained from lesions of animal to be vaccinated. Used for prevention, amelioration (make better), or treatment of specific infectious disease

Autoimmune disease: body becomes intolerant of its own cells; produces an immunogenic response against self-antigens; One organ is affected, or many tissues

Avascular: lacking blood vessels in body tissue

Avian: Pertaining to birds

Avulsion: tearing away of a structure or part

Axilla/axillary: region under the wing, between the body and the wing; wingpit; underside base of wing extending to ventral wing lining; muscles in the area important to flight, the axilla (refer to Wing Anatomy)

Axillary feathers/Axillars: Feathers located at the underside base of a bird’s wing; the long, stiff covert feathers covering the ventral base of the wing in the “armpit” or axillary area. (refer to Wing Anatomy)

Azotemia: increased nitrogenous waste products in blood as a result of kidney insufficiency/disease

B-Cell: or B-lymphocyte. Produces antibodies, generated in the Bursa of Fabricus; a white blood cell lymphocyte, formed in bone marrow in mammals and present in blood and lymph, that creates antibodies in response to a specific antigen. B cells or B lymphocytes are a type of lymphocyte in the humoral immunity of the adaptive immune system. B cells can be distinguished from other lymphocytes, such as T cells and natural killer cells (NK cells), by the presence of a protein on the B cell’s outer surface known as a B cell receptor (BCR). This specialized receptor protein allows a B cell to bind to a specific antigen. In birds, B cells mature in the bursa of Fabricius (the name of “B” cells comes from the name of this organ).[1] In mammals, immature B cells are formed in the bone marrow.[2]

The principal functions of B cells are to make antibodies to help antigens, to perform the role of antigen-presenting cells (APCs), and to develop into memory B cells after activation by antigen interaction. B cells also release cytokines (proteins), which are used for signaling immune regulatory functions.

Back/interscapular region or dorsum: the dorsal area from the neck to the rump, between the wings

Bacteria/bacterium: one-celled organism, may cause disease, round, rod-shaped, spiral, or filamentous, unicellular or noncellular bodies, often aggregate into colonies; may exist as freeliving organisms in soil, water, organic matter, or as parasites in live bodies of plants; some produce disease, most perform necessary functions such as digestion, fermentation (breakdown of carbohydrates by microorganisms.)

Bacteremia: bacteria in blood

Bacterial loading: normal avian skin contains fewer bacteria than mammals, less need for cleansing

Bactericide/bactericidal: kills vegetative bacteria but not mycobacteria (fungi) or spores

Bacteriostatic: inhibits growth or reproduction of bacterial organisms without necessarily killing them or their spores

Bacteriophage: virus that infects only bacteria

Bacteriuria: bacteria in urine

Barb: parallel feather rays branching out from each side of rachis

Barbicel: hooked projection extending from and interlocking with the barbules of a feather

Barbules: hooked branches extending from each side of feather barb, fasten adjacent barbs together

Barium Study: procedure, pet swallows barium or given as enema, x-ray exams to locate 9 disorder of esophagus, stomach or intestines

Baroreceptor: sensory nerve terminal that is stimulated by changes in pressure, as those in blood vessel walls; reflexes triggered by change in pressure, usually refers to blood pressure

Barraband Paralysis syndrome/spastic Leg paralysis; parrot disease of small number of birds in aviary; presents as sudden onset of paralysis of both legs, from mild weakness to whole limb extending stiffly behind the bird, clenched toes; bird’s general health not affected, eats and behaves normally; cannot balance, is ataxic in more severe cases, walks on hocks or with beak; cause unknown, but calcium, vitamins A, B1,2,6, and E deficiency suspected esp in allseed diets

Bars: Rows of distinctly colored feathers running across the bird’s body

Basal: outer edges of a bill or the outer primaries

Basal cell carcinoma: most common skin cancer; rarely metastasizes or kills, but causes significant destruction and disfigurement by invading tissues; abnormal, uncontrolled growths or lesions that arise in basal cells (deepest layer of epidermis— outmost layer of skin); look like open sores, red patches, pink growths, shiny bumps or scars; caused by UV exposure

Basic plumage: Plumage attained by the prebasic molt

Basilic vein: in upper arm near bicep muscle

Basophil: a leukocyte that cleans up debris

Basophilia: abnormal increase in basophils in blood

Basophilic intranuclear inclusion bodies: white blood cells going to the nucleus of the cell; the bodies are round, oval, or irregularly shaped, in cytoplasm and nucleus, as in viral diseases, e.g., poxvirus

Beak (bill): composed of the maxilla (upper) and mandible (lower); movable in parrots due to elastic zones in facial bones; rasplike ridges run transversely inside maxilla for cracking nuts; dermal and epidermal layers contain calcium and keratin; bill-tip organ, sensitive and used for feeling environment; allows bird to discriminate between food and other particles; nerve endings for mandible are in channels that can be seen as white dots in black beak; never cut them

Beak Overgrowth: Overgrowth of the maxilla or mandible; usually the maxilla (upper beak.) Some birds need their beaks trimmed; Other birds keep their beaks in shape by eating hard foods, grooming, climbing, chewing on wood, and rubbing the beak on a slightly abrasive surface. An overgrown beak can be the result of health problems including trauma, developmental abnormalities, nutritional imbalances, polyomavirus-like infection (finches), or liver disease (especially in budgies).

Beard: line of feathers hanging from a male turkey’s breast

B-cells or lymphocytes: mature in the Bursa of Fabricus in birds; vital part of immune system, specifically the humeral immunity branch of the adaptive immune system; can be distinguished from other lymphocytes such as T-cells and natural killer cells (NK cells) by the presence of a protein on the Bcell’s outer surface known as a Bcell receptor (BCR). This protein allows a B-cell to bind to a specific antigen; its functions are to make antibodies against antigens and develop into memory B cells after activation by antigen interaction. They also have a suppressive function.

Benign: mild illness or nonmalignant tumor; benign tumors have well-defined edges and grow slowly

Beta blockers: Heart meds which block beta receptors in heart; beta receptors receive signals to increase heart rate; if rate is too fast or uneven, beta blockers help stabilize the rate and rhythm of contractions

Beta-carotene: plant pigment which converts to Vt. A

Beta-lactamases: Enzymes produced by some bacteria which inactivate certain types of penicillin; makes the bacteria resistant to them

Bib: colored region seen below the chin of a bird

Bile: yellow-green fluid produced in liver, stored in gallbladder in ratites, stored in small intestine in psittacines; emulsifies fats

Bile acids: only specific test to liver disease in birds; compounds produced by liver are bound to amino acids and excreted in the bile in small intestines to aid in digestion of fats; Most are reabsorbed in small intestine, enter the portal system and are taken up by liver to be recycled; increase in bile acids indicates poor liver function

Biliary duct: related to bile or transport of bile; affecting a bile duct or the system of ducts in the liver

Bilirubin: orange-yellow pigment in bile that is a product erythrocyte breakdown; normally excreted with urine or feces; buildup in body causes jaundice; released by liver in bile

Biliverdinuria: dark green bile in urine indicative of liver disease; increased excretions of it indicate hepatitis; caused by obesity and high-fat diet

Biocide: an agent that kills all pathogenic and non-pathogenic living organisms, including spores; includes insecticides and any compound toxic to living things

Biopsy: removal of small piece of tissue for microscopic exam

Bipedal: stands on 2 legs

Bleaching: lightening of the plumage colors caused by exposure to sunlight

Blepharitis: infected or inflamed eyelid

Blepharospasm: spasm of eyelids resulting in complete closure of eyelids due to pain, e.g., scratched cornea

Blood cells: new cells generated every 4-6 weeks; Low BC due to viral infections; high BC due to stress, disease

Blood FeatherBlood feather: new feather has venous and arterial blood supply; thick, purple appearance; as feather matures, blood supply recedes  (Also refer to “Pulling a Blood Feather – Instructions“)

Blood fractionation is the process of fractionating whole blood, or separating it into its component parts. This is typically done by centrifuging the blood. The resulting components are: a clear solution of blood plasma in the upper phase (which can be separated into its own fractions; the buffy coat, which is a thin layer of leukocytes (white blood cells) mixed with platelets in the middle; and erythrocytes (red blood cells)

Blood gases: e.g., oxygen or CO2 in blood

Blood glucose levels: high levels (over 900 mg/dl) cause diabetes mellitus; Below 150 life-threatening

Blood sampling: taken from jugular vein or ulnar vein, not toe clip

Body cavities: hollow spaces that contain and protect internal organs:

  • Cranial: protects brain
  • Spinal: contains spinal cord in spinal column
  • Thoracic or chest: protects heart and lungs between neck and diaphragm
  • Abdominal: contains major digestive organs between diaphragm and pelvic cavity
  • Peritoneal: hollow space within abdominal cavity between parietal (walls of the) peritoneum and visceral peritoneum
  • Pelvic: space that contains the reproductive and some excretory systems (bladder and rectum) and organs bounded by pelvic bones

Bolus: soft, round mass of chewed food; a lump; round mass of medicinal material, larger than a pill; a second, larger dose of medication; also ball of leftover material after ingestion of prey

Bone tissue (Bird): Colored scanning electron micrograph (SEM) of cancellous (spongy) bone from a robin. This tissue, found in the interior of bones, is characterized by a honeycomb arrangement of trabeculae (columns) and spaces. This honeycomb structure provides support and strength to the bone.

Bone callus: localized hyperplasia of the horny layer of the epidermis due to pressure or friction; an unorganized network of woven bone formed about the ends of a broken bone; it is absorbed as repair is complete (provisional callus) and ultimately replaced by true bone (definitive callus); in osteolomy, bony and cartilaginous material forming a connecting bridge across a bone fracture during repair; happens within one to two weeks of surgery

Bone Marrow: soft tissue composed of blood vessels and connective tissues found at center of bones; primary function is blood cell production. Only long bones and some ribs are pneumatic and are filled with air and not marrow. The rest are not pneumatic.   See Appendix / Bird Skeleton

Bone Marrow dysplasia: Myelodysplastic syndrome; preleukemia; a diverse collection of hematological medical conditions that involve ineffective production (or dysplasia) of the myeloid class of blood cells; not a single disease but group of diseases that affect blood cell formation; in all forms of MDS, a bone marrow problem leads to low levels of blood cells circulating in the bloodstream

  • Anemia: low level of RBCs
  • Leukopenia: low level of WBCs
  • Thrombocytopenia: low level of platelets

Bone marrow suppression: cells of bone marrow which produce erythrocytes, leukocytes and platelets are inhibited; a result of certain drugs, such as anti-cancer agents

Booted: not divided into scales (tarsus); the tarsus of certain birds; covered with a continuous, horny, boot-like sheath; having an undivided tarsus covered with a horny sheath

Botulism, type E: the type that targets waterbirds who feed on fish

Brachial: the upper arm; the area supported by the humerus

Brachygnathia: abnormal shortness of the mandible results in maxilla that protrudes

Bradycardia: abnormal slowing of heart rate

Bradypnea: abnormally slow respiration rates

Brain: there are 3 major divisions of the bird’s brain:

  • the Optic lobe (chiasma),
  • medulla oblongata, and
  • olfactory lobe

Branchus/Bronchi: large air passages of lungs

Breast: chest or pectoral region Area of a bird located between the chin and the belly

Bronchitis: inflammation of bronchial passages

Brood: combined nestlings in nest; sitting on/hatching young; sheltering to keep warm and for protection

Brood parasites: Species of birds who deposit their eggs in the nest of other birds, to be fed and raised by other families.

Brood PatchBrood patch: area over breast that becomes thickened, vascular and featherless during brooding period; transfers heat from hen to eggs

Brood reduction: feed most vigorous, biggest ones first; strongest survive in low food supply years, all survive in good years

Bucky technique: set up instrument in line with 2 marks for radiography

Buffy coat: reddish-gray layer of consisting of white blood cells and platelets observed above packed red cells in centrifuged blood; the superficial layer of yellowish or buff coagulated plasma from which the red corpuscles have settled out in slowly coagulated blood

Bulbar: bulb shaped, pertains to medulla oblongata

BumblefootBumblefood (pododermatitis) lesions on bottom of feet due to incorrect perching and rough perches

BUN: Blood Urea Nitrogen; blood test that estimates kidney function

Bursa/Bursal: sac-like body cavity, located between moving parts, e.g., elbows, shoulder, knee; fibrous sac that acts as a cushion to ease movement in areas of friction

Bursa of Fabricus:, a specialized organ that is necessary for the immune system. The bursa is an epithelial and lymphoid organ that is found only in birds. It is attached to the large intestine. The bursa is active in young birds. It atrophies after about six months.

C-Fiber: an unmyelinated nerve fiber, esp of autonomic system

Cachectic/cachectin: protein released by activated macrophages as an immune system defense; when it is overwhelmed it causes cachexis or toxic shock

Cachexia: general ill health with emaciation, usually occurring with cancer, chronic infection, disease; extreme weight loss

Calcaneal tendon: Achilles tendon, tendon on tibiotarsus

Calcified: hardening of tissue through the influx of calcium, usually a result of chronic inflammation

Calidridine: group of closely related sandpipers, primarily of the genus Calidris

Callus: bulging deposit around bone fracture; may turn to bone

Cancellous bone: (trabecular or spongy bone); a type of osseous tissue that forms bones. Has a higher surface area than compact bone (other type of osseous tissue), but is less dense, softer, weaker, less stiff; occurs at ends of long bones, proximal to joints and within interior of vertebrae. Cancellous is highly vascular and contains red bone marrow where hematopoiesis (production of blood cells) occurs.  Please refer to: Skeletal System / Bone Anatomy

Candida: genus of yeast; causes disease; infection is candidiasis

egg candlingCandling / Egg Candling: view of egg for fertility

Cannula: metal tube inserted into body to draw off fluid or deliver medication; tubular shaped, contains trocar (sharp, pointed instrument for piercing)

Canthus/canthi: corners of the eye; inner, nasal, or medial canthus holds the tear ducts, temporal, outer, or lateral canthus is closer to the ear

Cap: top of head, color can differentiate between similar but different species

Capillaria/capillariasis: infestation by nematode : internal parasitic worm

Carcinogen: causes cancerous growths in living tissue

Carcinoma: malignant cancer arising from epithelial tissues, e.g., skin, intestinal tract, bladder

Cardiac failure: weakness, anorexia, tachypnea (rapid breathing), dyspnea (shortness of breath), coughing, abdominal distension due to hepatomegaly and ascites, diagnosis determined by arrhythmia or murmur, x-ray, treatment: furosemide is a loop diuretic (water pill) that prevents your body from absorbing too much salt, allowing the salt to instead be passed in your urine. dose, subcutaneous fluids, oxygen, ultrasound

Cardiac infarction: localized area of necrosis caused by interrupted blood supply to heart

Cardiomegaly: enlarged heart

Cardiomyopathy: heart muscle disease; not of valves or congenital defect; leads to decreased function with no known cause

Cardiopulmonary: of heart and lungs

Cardiovascular system: of heart, blood, blood vessels

Carina: keel bone, sternum, or breast bone. Bone that protrudes a little from the chest

Carotenoids: pigments in the feathers that are derived from the bird’s diet; produce these colors: bright yellow, bright red, orange; occur mostly in flight feathers, back and breast plumage

Carpometacarpus: fused bones of the hand (manus) joint

Carrier: animal harbors infectious organism e.g., virus, bacteria, parasite. Animal appears healthy, but can transmit organism to others by direct contact or release of organisms into environment in stool, urine, respiratory secretions …  Non-shedding carrier: harbors disease but doesn’t show symptoms and is not contagious; as in latent infection

Cartilage: gristly connective tissue, more elastic than bone, used in flexible portions of skeleton. Hyaline, Elastic

Carina or keel; the projection of the breastbone

Caruncle: small, fleshy, comb-like tissue on turkey’s forehead

Caseous: having the appearance of cheese, one of the forms of tissue death (necrosis); e.g., xanthomas

Cast/casting: things that are shed, e.g., skin feathers, can cause renal disease, leftover parts of prey thrown up by raptors, owls

Catabolism: breaking down of muscle or other tissue due to malnutrition or starvation; destructive form of metabolism involving release of energy and resulting in true excretion products

Cataract: cloudiness of lens of eye, reducing vision, giving eye pearly appearance

Catecholamine: organic compound, chemically related neurotransmitters, as epinephrine and dopamine, that have effects on sympathetic nervous system; Some catecholamines are produced naturally by the body and function as key neurologic chemicals; catecholamines play an important role in the body’s physiological response to stress. Their release at sympathetic nerve endings increases the rate and force of muscular contraction of the heart, thereby increasing cardiac output and constricting peripheral blood vessels, resulting in elevated blood pressure, high blood glucose levels, hyperglycemia, lipids; affects metabolism

Celiac: the abdomen or stomach areas

Cell-mediated immunity: a result of special lymphocytes directly killing the foreign invader, or T-Cell lymphocytes releasing special chemicals which activate macrophages to kill the invader; compare with “humeral immunity”

Cell mitosis: cell division

Cellulitis: diffuse inflammation of solid tissue, redness, swelling, pain, loss of function in affected area

Celum/Coelum: principal body cavity of trunk; contains peritoneal, pericardial and pleural sacs

Centrifuge: machine that rapidly spins liquid samples and separates out particles by their density

Cephalic edema: fluid in the head

Bird cere (1) and nares (2) Operculum inside the nares, Nasal fossa Cere; fleshy area enclosing nares, smooth, featherless; highly vascularized; found mostly in birds of prey, pigeons and parrots.

Cerebellum: part of brain located on brainstem, controls coordination

Cerebrum: largest portion of brain, performs higher cognitive functions, sits in front part of cranial cavity

Cervical: area and structures of the neck

Cervicocephalic: area of bones of the neck close to the anterior part of head

Cestode: tapeworm parasite

Chalaza/chalazae: gelatinous, milky white, stringy coils of albumen that surround and protect egg yolk; visible at either end of yolk as twisted cords; attached to far ends of eggshell and form a suspension system for the yolk that allows it to rotate throughout embryonic development; stabilizes yolk and keeps it from floating against the upper shell’s surface. Keeps the germinal disk in the upward position so it remains next to the heat produced by the incubating parent above

Cheek: between lore, eye, auricula and mandible

Chelation: binding of a substance to a metal, thus helping the body to remove it

Chemosis: swelling and congestion of the conjunctiva due to edema or circulatory problems; includes excessive secretions and abnormal blood-filled tissue; caused by Chlamydia Psittici

Chest: front of body containing keel and major flight muscles

Chick: the fledglings of certain bird species.

Chin: below beak; does not protrude

Chlamydia/chlamydiophilia psittaci/Chlamydiosis;parrot fever/ornithosis: bacterial organism responsible for psittacosis; gram neg. pathogen; zoonotic, systemic; signs: diarrhea, ocular and nasal discharge

Choana/choanae/choanal: slit in hard palate of mouth, connects nasal passages/cavity with oropharynx; numerous projections or papilla found around edge of choanal slit; glottis fits snugly into the slit when bird closes its mouth to close connection from nostrils to windpipe

Choanal papillae: several tiny whitish projections that line the choanal slit; should be sharp; blunting or absence attributed to hypovitaminosis A or respiratory illness; purpose is to block debris from going up into the choanal

Cholesteatoma: cyst-like mass with lining of stratified, squamous epithelium filled with debris (cholesterol); occurs in brain and CNS.

Cholesteatosis: fatty degeneration due to cholesterol esters (Esters have a very sweet fruity smell.) Naturally occurring esters are found in fruits. An ester is a product of the reaction of an acid (usually organic) and an alcohol.

Chondroitin: it is a molecule that occurs naturally in the body; the major component of cartilage — the tough, connective tissue that cushions the joints; helps keep cartilage healthy by absorbing fluid (particularly water) into the connective tissue. It may also block enzymes that break down cartilage, and it provides the building blocks for the body to produce new cartilage.

Chorioallantoic/chorionic membrane (CAM) forms during embryonic development; lines inner egg shell surface; has capillaries through which oxygen and CO2 gases are exchanged between embryo and outside air.

Chorioretinitis/choroid retinitis: inflammation of the choroid (thin pigmented vascular coat of eye) and retina of eye; signs: floaters, blurred vision, pain/redness, sensitivity to light, excessive tearing;

Choroid/choroidea: middle, vascular coat of eye, between sclera and retina; contains connective tissue and blood vessels; supplies nutrients to inner parts of eye

Christalloid: resembles a crystal; solution containing electrolytes which diffuse into all body fluid compartments; e.g., Ringer’s solution and dextrose in water

CBC: Christmas Bird Count

Chronic: illness of long duration slow progression of symptoms

Chronicity: state of being chronic

Chronic superficial keratitis: chronic eye condition; blood vessels grow across cornea (clear surface of eye); cornea looks hazy and red; eventually takes on dark pigment; aka “pannus”

Cicatrix/cicatrices: fibrous scar tissue left after a wound has healed

Ciliary muscle: striated muscle that controls eyelashes (celia)

Circovirus: causes PBFD

Circumscribed: surround by a boundary or is within a certain space

Cirrhosis: liver disease caused by replacement of damaged cells with connective tissue; severe scarring can eventually cause liver failure; caused by hepatic lipidosis

Cicatrix: a scar resulting from formation and contraction of fibrous tissue in a wound

Cline: a species of birds that is spread out over such a large distance that birds at one end will not associate with the others

Clinical: medical matters e.g., history, signs; also means bird is presenting symptoms

Clinical diagnosis: cause of disease based on physical/visual signs

Clinical study/trial: planned exam of effectiveness of new drug or treatment; as compared to control group not receiving the treatment

Cloaca: common tube-like chamber or structure through which feces, urine, urates, fluids, eggs pass; above vent;

Cloacal Prolapse or everted cloaca: internal tissue turned outward or inside out.

Cloacal compartment: divided with 3 poorly-defined compartments: Copradeum, Urodeum and Proctodeum

Cloacal prolapse: inversion of the cloaca due to muscle weakness, usually from chronic egg laying

Cloacal kiss: copulation; male bird copulates many times to make sure he is father of at least some of the young in his nest

Cloacal papilloma: gross lesion; red proliferative mass commonly originating from just inside the rim of the cloacal opening.

Cloacapexy: incision made in abdomen to suture cloaca to caudal border of sternum (abdominal wall) after prolapse

Cloaca bursa (Bursa of Fabricus): lymphoid gland of cloaca, believed to function in disease resistance, closing or disappearing as bird ages

Cloacal circlet/anal pteryla: the two rows of feathers arranged in concentric circles around the cloaca

Clonic/clonus: alternating involuntary muscle contractions in rapid succession, upper motor nerve disease

Clostridium Perfringen: type birds get; anaerobic, spore-forming bacteria, causes enteritis; both giardia and clostridium cause malabsorption of Vit. E

Clotting factors: protein components in blood which help it clot; clotting is complex mechanism; result of chain of chemical reactions and work of platelets; requires Vit. K

Clutch: complete set of eggs belonging to the female

Cnemial: relating to shin or shin bone

Coagulopathy: a condition affecting the blood’s ability to form a clot; defect in body’s mechanism for blood clotting

Coaptation: joining or adjustment of parts to one another, as broken bone

Cob: male swan

Coccus/cocci: spherical microorganism; any bacterium that has a spherical, ovoid, or generally round shape. It is one of the three distinct bacterial shapes, the other two being bacillus (rodshaped) and spiral-shaped cells; gram-positive, stain purple See Coccidium/coccidia/Coccidiosis protozoan intestinal parasite, lays oocysts (eggs)

Coccidiostat:drug that inhibits growth of coccidia

Cock: male bird

Coliforms: coliform bacillus; various species of bacteria inhabiting colon

Collagen: fibrous, insoluble protein that forms part of the supportive framework of skin, bone, ligaments, cartlage, tendons; also in vitreous humor of eye as stiffening agent

Collar: upper part of neck, behind crown, aka hindneck and nape

Collimate/collimation/collimated beam: radiographic term for adjusting accurately the line of sight

Colloidal solution: semi-solid suspension, uric acid secretion; glue-like solution used to manage shock; increases osmotic pressure and volume of plasma

Colonial: birds of the same species who build multiple nests in colonies

Comb: fleshy skin on rooster’s crown

Commensal relationship: symbiotic relationship in which an organism lives on or within another organism, derives benefit from it, without harming … An example of commensalism: cattle egrets foraging in fields among cattle or other livestock. As cattle, horses and other livestock graze on the field, they cause movements that stir up various insects. As the insects are stirred up, the cattle egrets following the livestock catch and feed upon them. The egrets benefit from this relationship because the livestock have helped them find their meals, while the livestock are typically unaffected by it.

Comminuted fracture: bone fracture in which the separated parts are splintered or fragmented, divided into small parts, powdered or pulverized; at least 3 bone pieces involved

Commissure/commisural point/gape: line formed by meeting of maxilla and mandible; hinge where the two meet; psittacines able to move both but most birds only move mandible

Communal roost: sleeping place for gathering of birds

Compensation: making up for defect of function or structure; e.g., counterbalancing;

Complete Blood Count/CBC: Count of total number of cells in a given amount of blood; includes erythrocytes and leukocytes; tests for abnormalities in blood

Compressed: flatttened from side to side Computerized Tomography Scan (CT or CAT scan): radiological imaging procedure that uses 2-rays to produce “slices” through body; computerized axial tomography.

Concha/conchae: turbinate bone in nose; spongy bones in nasal passages; includes sinuses; hollow spaces in head where infection may clog it with liquid, mucous, abscess, or debris

Concretion: solid, hard mass, lith

Condyle: articular prominence on bone, rounded projection of a bone that anchors muscle ligaments and articulates with adjacent bones; e.g., occipital area (back of head), knuckle, or elbow; smooth surface 15 area at end of a bone, forming part of a joint

Confluent: flowing together, meeting, combining form one

Congeners: something of same type; birds that are related to one another because they belong to same class, group, or type; e.g., animals in same genus

Congenital: present at birth

Conjunctiva: thin membrane which lines inside of eyelids and covers part of eyeball

Conjunctivitis: watery eye discharge, swollen lids, red conjunctiva; paresis, weak jaw tone, mostly in lutinos, inherited, non-infectious

Connective tissue: adds support and structure to body part; holds organs in place and binds parts together … Types: dense connective tissue such as bone, cartilage, tendons and ligaments; loose connective tissue is blood

Conspecific: birds of the same species

Constricted Toe Syndrome

Contact call: sound produced by bird that informs nearby birds of caller’s location; seeking response; by mates or bonded birds to other birds or humans

Contour feathers: the feathers that cover most of the bird, not including the flight feathers

Contrast agents: substance given orally or injected that makes affected tissue easier to identify on x-ray. E.g., barium

Contusion: bruise: unjury to underlying tissues without breaking skin; gives skin greenish color

Cooperative breeding: More than two birds of the same species feeding young birds from one nest

Copralith/fecalith: hard fecal mass

Copradeum: top chanber of cloaca, largest of the three; same as rectum; holds fecal matter until defecation

Copraphagia: eating feces

Coracoid bone: extra bone in shoulder; acts as strut to counterat pressure of downbeat of wings

Cornea: clear part of front of eye, lets light in

Cornified: having a keratinous or horny covering

Cortex: outer layer of bone or organ as opposed to the inner layer; more brittle in birds than mammals

Corticosteroids: natural steroid: hormone produced by adrenal gland and involved in metabolism and immune response; any of the hormones produced by cortex of adrenal glands; also produced synthetically; their action allows many biochemical reactions to proceed at optimum rates. Important to almost every function of cells and organs; Two groups:

  • Glucocorticoids –regulate protein, carboydrate, and fat metabolism
  • Mineralocorticoids—regulate electrolyte balances

Costal: ribs or rib cage

Cortisol: the main glucocoritcoid: hormone naturally produced by adrenal glands; sythesized as hydrocortisone, used to reduce inflammation

Countersinging: singing of one bird in direct response to another bird singing among the same species

Courtship displays: performace to attract mate, maintain pair bond, stimulate breeding behavior

Coverts (tectrices): smaller feathers covering large wing and tail feathers; partly cover flight feathers; streamlines bird’s profile, reduces frictional drag in flight

Cranial: pertaining to the head

Cranial nerves: birds have 12 pairs of cranial nerves which leave the cranium through special holes in the structure; each innervates a specific area of the body

Craniofacial hinge: hinge at cere allows maxilla and mandible to move at same time; flexible connection between skull bones which permits upper jaw to be raised as same time as mandible is depressed; well developed bwtween the nasal and frontal bones in psittacines

Creche: gathering of hatchlings in a nesting colony, tended to by different adult birds

Crepitant/crepitus: making a cracking crinkly, or grating feeling or sound under the skin, around the lungs, or in the joints. Crepitus in soft tissues is often due to gas, most often air, that has penetrated and infiltrated an area where it should not normally be (for example, in the soft tissues beneath the skin). Crepitus in a joint can indicate cartilage wear in the joint space.

Crepitant rale: cracking sound made during inspirtation in lung diseases

Crepuscular: birds that are active at twilight hours

Crest: tuft of feathers on head; larger in males; increases visibility to predators and potential mates, females evaluate potential mate by his crest; the more elaborate the crest, the healthier the bird is

Crissum: feathers in a triangular area on undersurface of bird between vent and pygostyle; can tell whether a bird is adult or juvenile by cruissum; adult females have dusky edge to most of the featheres there; juvenile females have nearly pure white feathers

Crissom/undertail coverts, or circumcloacal region: the loose feathers that surround the cloaca, including the undertail coverts that cover the ventral base of the tail.

Crop/ingluvies: outpouching of esophagus between cervical and thoracic parts of esolphagus; oreinted transversely across neck

Crop ilius: obstruction Crown: top of head, holds the crest

Cruciate ligament: cross-shaped

Crural feathers: on femoral tract which covers outer surface of thigh in a diagonal strip from knee joint upward toward pygostyle; rest of leg contour feathers are included within the crural tract.In some large birds and in birds with heavily feathered legs, additional metatarsal tract is identified, covering tarsometatarsal area of lower leg

Crust: area of dried fluid or cells on skin; may be blood, serum, pus, or medication

Cryptic: a bird’s plumage that is able to blend into the local surroundings or habitat

Crystalloids: crystal-like, forms solutions that can pass through semi-permeable membranes as in dialysis; opposite of colloid which does not dissolve and does not form a true solution; given for shock, contains electrolytes and non-electroytes which will diffuse in all body compartments; e.g., Ringer’s solution and 5% dextrose in water

Culmen: uppermost central ridge of maxilla; no specific function: males’ are larger

Culture: propagation of microorganisms or living tissue cells in media conducive to growth or reproduction

Curette: surgical tool for cleaning nares and other procedures

Cutaneous: relating to skin

Cyanosis: blue-gray or purple discoloration of skin and/or mucous membranes; caused by deficiency of oxygen and excess of carbon dioxide in blood; due to heart disease, obstruction of airways, or certain drugs’ overdose

Cycle: the yearly cycles a bird will have to mature before developing adult plumage

Cygnet: young swan

Cyst: abnormal mass under skin surface; abnormal sac-like structure lined with cells which produce a liquid, thick material

Cystadenomas: benign cystic tumor or neoplasm that exhibits glandular differentiation: cystoma plus adenoma;

Cystectomy: removeal of urinary bladder

Cystitis: inflammation of urinary bladder

Cystocentesis: procedure to obtain uncontaminated urine sample; needle is passed through abdomen into bladder, urine is collected in a syringe

Cystopexy: fixing urinary bladder to abdominal wall

Cytoplasty: repair of uninary bladder.

Cystotomy: surgical incission into urinary bladder

Cytokines: any of a group of small, short-lived proteins that are released by one cell to regulate the function of another cell, thereby serving as intercellular chemical messengers.

Cytokines effect changes in cellular behavior that are important in a number of physiological processes, including reproduction, growth and development, and injury repair. However, they are probably best known for the roles they play in the immune system’s defense against disease-causing organisms.  Compounds produced by certain cells act as messengers to control the action of lymphocytes and other cells in an immune response

Cytology: study of microscopic appearance of cells, esp to diagnose abnormalities and malignancies; often refers to microscopic examination of a sample taken from skin or lesion to find cause for the condition

Cytoplasm: thick substance surrounding the nucleus of a cell; is the physical basis of all living activities in the body

Cytoplasmic: refers to the protoplasm surrounding the nuclus of a cell

Cytosis: act of destroying cells

Cytotoxic: poisonous to cells

Dabbling: waterfowl’s method of using the bill along the surface of the water to screen for food

Deaminate: to remove the amino group from a compound

Debillitation: weakening of body

Debridement: removal of foreign matter and dead tissue from a wound 

Decompensation: inability of diseased organ to compensate for its defect; failure of body to make up for defects of function or structure

Decubitus: any position taken by lying in bed

Decubitus ulcer: pressure or bed sore; produced by local interference with circulation; usually occurs over a bony prominence, such as sacrum, hip, heel, shoulder, or elbow; caused by excessive/prolonged pressure produced by weight of body or limb

Decurved: a bill that is curved downward toward tip, like a curlew’s

Decussation: bands of nerve fibers crossing, passing between centers on opposite sides of CNS, X-shaped


Definitive diagnosis: scientific identification of cause of disease

Dehiscence: bursting open, as of contents; incision dehiscence: opening of an organ to discharge its contents; parting of the lips of a surgical wound

Dermatitis: inflammed skin

Dermatome: area of skin supplied with afferent nerve fibers by a single dorsal spinal root; A dermatome is an area of skin that is mainly supplied by a single spinal nerve; The surface of the skin is divided into specific areas called dermatomes,” which are derived from the cells of a somite. They are necessary for assessing and diagnosing the level of spinal cord injury. These cells differentiate into the following 3 regions:

  1. myotome, which forms some of the skeletal muscle
  2. dermatome: which forms connective tissues, including the dermis
  3. sclerotome, which gives rise to the vertebrae.

Desertion: abondoning the nest

Desiccation: drying out

Desquamation: to remove, scale or peel off in small pieces, esp skin; can be naturally occurring

Detritis: (cellular) particulate matter produced by or remaining after the wearing away or disintegration of a substance or tissue

Diabetes mellitus: metabolic disease caused by failure of pancreas to produce insulin (glucogen for birds) , a hormone that allows blood sugar (glucose) to be taken up by cells that require it to function

Diagnostic feathers: the particular feathers that determine the species of the bird


Dia’physis/diaphy’sial: shaft of long bone, between the ends, to grow between

Diarrhea: abnormally fluid-laden fecal discharge; result is poor absorption of water, nutritive elements and electrolytes

Diasthesis: unusual susceptibility or predisposition to a disease

Dichromatism: the normal occurrence of two different colorations in the same species due to neither sex nor age

Differential diagnosis: all the possible diseases that could be causing the symptoms

Differential WBC: Percentage of different types of white blood cells in a sample

Differentiate: marked or formed differently from other cells; distinct; changed from a generalized form into a form specialized for a tissue, organ or other body part

Diffuse: not limited or localized, spread widely

Digitegrade: walks on toes rather

Digits: the fingers; in birds, the remnants of four digits are present than all foot bones

Dihedral: wings held in V-shape profile while in flight/gliding

Dilated cardiomyopathy: heart enlarges but heart muscle thins

Dimorphis/dimorphic: physical characteristics which differentiate male from female; distinct difference in plumage or color

Diphtheritic lesions: lesions in membranes which resemble human diphtheritic lesions; formed in air passages, esp throat, necrosis of superficial layers of mucosa combined with inflammatory exudate on mucosa

Discrete: separate, unconnected parts, not spread out, limited to one area

Disseminated: scattered, distributed over an area

Disseminated Intravascular coagulation: DIC: hemorrhagic disorder that occurs following the uncontrolled activation of clotting factors and fibrinolytic enzymes through small blood vessels; results in tissue necrosis, bleeding, death

Distal Band (aka subterminal band = the stripes on the tails of certain birds. The stripe is located just before the tip.) 

Distal or superior umbilicus: area by the afterfeather. Proximal 18 or inferior umbilicus is the part going into the feather follicle.

Distraction display: shown by the parent bird to attract predator away from nest.

Diuresis: increased urination caused by excessive intake of fluids, or a drug; unusually large urine output

Diurnal: birds that feed during daylight hours.

Diverticulum: circumscribed pouch or sac occurring naturally, usually in reference to the colon

Diverticulum in bones: air sacs that extend into the long bones, making them pneumatic or air-filled

Down feathers: soft, fluffy feathers whose barbs do not cling together; they trap more air and provide extra insulation; young birds have natal down before molting into their juvenile plumage; protects skin from moisture and pathogens

Drake: male of some species

Drift: polyethyline intermedullary bone fixation appliance; also viral drift–gentotypes

Dry eye: Keratoconjunctivitis Sicca (KCS); occurs due to inadequate tear production; includes thick, yellowish discharge from eye.  Also refer to Eye Diseases

Dump nesting: laying eggs in nests of other birds, usually the same species

Duodenum: top part of small intestine from pylorus to liver; accepts bile and pancreatic fluids then joins large intestine

Dyschezia: difficulty defecating

Dyscoria: abnormal shape or form of pupil or reaction of two pupils

Dyscrasia: unspecified blood disorder; morbid general state resulting from presence of abnormal material in the blood; usually seen with disease affecting blood cells or platelets. Present with a WBC of over a million.

Dysgerminoma: solid malignant ovarian neoplasm derived from undifferentiated germinal cells

Dyspharyx: proventricular worm/parasite

Dysphagia: difficulty swallowing or eating

Dysplasia: abnormal growth of cells, tissues, organs

Dyspnea: difficult or labored breathing

Dystocia: inability to pass egg

Dystrophic/dystrophy: defective growth in size of an organ, tissue or cell; due to faulty or inadequate nutrition or development; weakening degeneration or abnormal development of muscle; muscles atrophy

Dysuria: difficult/painful urination

Cockatiel "Ear"Ears: facial discs, auricular meatus; rounded areas on cheek

Ear canal: tube that connects external ear with ear durm

Ear coverts: feathers covering the birds ears (see auricular coverts)

Ear drum: tympanic membrane, divides inner from outer ear; prevents infection from reaching inner ear; vibrates to amplify sounds

Eccymosis/eccymotic: swelling due to blood extravasation (escape into tissues); bruising, swelling on skin due to hemorrhage

ECG/EKG: Electrocardiogram; printout of analysis of electrical activity in heart; electrocardiography: graphic recording of the electrical actiivity of the heart, allows heart muscle action to be studied

Echocardiogram: image produce by performing ultrasound of heart

Echogenic: capable of generating or reflecting soundwaves, as in tests

E-coli: common gram-neg pathogen in birds; enteric bacteria; normal in some birds in small amounts; produces toxins/disease

Eclipse plumage: non-breeding plumage

Ectoparasites: flies, ticks, fleas, lice; inhabit exterior of host’s body

Ectropion: abnormal distortion of eyelid so that lower lid turns out, causing a pocket in which tears collect and run out

Edema/edematous: excessive accumulation of serous fluids in an organ,body cavity, or tissues; causes swelling (hyperemia)

Efficacious: effectiveness

Effusion: lymph or blood present in body cavities or tissues; a result of inflammation

Egg: ovum before and after fertilization; contains embryo, yolk, albumin

Egg callosity: egg tooth

Egg laying (chronic) and egg binding: caused by obesity, low calcium levels, chilling, lack of exercise, infection in oviduct; bird straining to pass egg; erect posture, swollen abdomen, egg palpable near vent; most common in hens with no mate

Egg tooth: short, pointed, calcareious (contains calcium 19 carbonate) structure on tip of maxilla that develops shortly before hatching; used to break out of shell; sloughs off or is reabsorbed within a few days after hatching

Electrocautery: electric instrument with very hot tip; applied to a tissue to make incision, remove a mass or stop bleeding

Electrolyte: a substanced in a solution; in body fluids

Electromyography (-gram): records electrical activity of muscle cells, records strength of muscle contraction; caused by electrical stimulation

Electrophoresis: process used in separation of proteins and nucleic acids; used to study diseases in which there are altered serum and plasma proteins

Elemental formulas: high caloric, protein fat and carb content; high osmolality, vary from requiring some digestion to requiring little to none (monomeric); formula is predigested (proteins hydrolyzed)

ELISA-A: fluorescent antibody serology test that detects diseases such as psittacosis, ABV/PDD; enzyme on a substrate pulls out blood serum; positive birds shed the organism only about 12% of the time, so neg does not rule out Psittacosis

Emaciation: loss of flesh through disease or starvation; severe weight loss resulting in 50% of normal weight

Emarginate: notched tail faither

Embarrassment: difficulty in function due to disease; failure or impairment of functioning; to interfere with or impede an organ or part;, e.g., fetal or respiratory embarrassment; distress; physiological difficulty of some kind

Embolic: the lodging of an embolus which may be a blood clot, a fat globule or a gas bubble in the bloodstream; can cause a blockage.

Embolism: sudden blocking of artery by a clot; brought to site by blood flow

Embryo: developing bird in egg

Embryonic development: biochemical processes, programmed by DNA, that take place within the egg through which a fertilized egg develops the specialized tissues and organs

Emesis: vomiting

Empirical: derived from or guided by and provable by experience or experiment alone, without using scientific method or theory, esp as in medicine; evidence that can be observed

Emulsion: mixture consisting of a solid or semisolid dispersed in a liquid

Encephalitis: inflammation of brain, often caused by virus

Encapsulated: enclosed by a protective coating or membrane, e.g., encapsulated bacterium, organ structure; fatty, cartilaginous or fibrous structure enclosing a part

Encephalopathy: degenerative brain disease; severe hepatic insufficiency, causes excitability, tremors, compulsive walking, head pressing, apparent blindness, coma, convusions, death

Endemic: found in a specific area or species; present in a community or among a group; birds that are only found in certain states or countries; disease prevailing continually in a region

Endocarditis: inflammation of endociardium (serous membrane that lines the cavities of the heart)

Endocrine gland: ductless gland which produces an internal secretion that is discharged directly into the blood or lymph and circulated to all parts of the body

Endogenous: produced or synthesized or caused by factors within the organism or system

Endoparasite: invertebrate or protozoan parasites that inhabit interior of host’s body or skin’s surface

Endophthalmos: sunken eye, backward displacement of eye in bony socket, caused by traumatic injury or developmental defect

Endoscope/endoscopy: long, flexible tube with lighted mirror and lens system attached (cannula); passed through body to view organs; uses fiberoptics: surgical procedure

Endosteal/Endostium: tissue lining of medullary cavity of a bone

Endotoxin: bacteria confined within body of bacterium and freed only when the bacterium disintegrates

Endotracheal tube: placed into trachea to allow oxygen and gases to be breathed into lungs

Enteral: pertaining to intestines

Enteral feeding: tube feeding through skin into intestine; allows nutrition to be forced into intestine

Enteric bacteria: normal or pathogenic flora in intestines

Enteric nervous system: (ENS) or intrinsic nervous system is one of the main divisions of the autonomic nervous system and consists of a mesh-like system of neurons that governs the function of the gastrointestinal system

Enteritis: intestinal inflammation/infection, esp small intestine

Enterobacteria: gram neg pathogen, mild

Enucleate/enucleation: to remove without cutting into the organ or mass; e.g., eyeball or tumor

Enveloped virus: covering of a protein capsid; can cause persistent infections; doesn’t live long outside of host; can change rapidly to evade immune system

Enzootic: diseases afflicting all animals in particular area

Enzyme: protein produced by cells which cause chemical changes in other cells but are not changed themselves; regulate production of chemical substances in body

Eosinophil/eosinophilic: granular white blood cell stained with eosin, elevated with parasites, allergies, tissue inflammation

Eosinophilia: more than usual number of eosinophils in circulating blood

Ependyma: epithelial membrane lining the ventricles of brain and canals of spinal cord

Ependimoma: a glioma (tumor arising from neuroglia) arising in or near ependyma

Epicardial: tissue around the heart

Epidermis: top layer of skin

Epidemic: disease attacking many in community simultaneously; introduced from outside

Epidemiology: study of factors involved in diseases in a community

Epiphora: excess tears in lachrymal glands due to obstruction of gland

Epiphysis/epiphyte: end of long bone, wider than the shaft, all cartilage, separated from shaft by a cartilaginous disk

Epistasis: stoppage of secretion or discharge; e.g., nose bleed, hematoma, tumor or swelling containg blood

Epistaxis: nose bleed

Epithelium/epithelial: membranous tissue composed of one or more layers of cells that cover most internal and external surfaces of body and organs; layer between an organism and its tissues or organs and their environment (e.g., skin cells, inner linings of lungs or digestive organs, outer lining of kidneys); encloses and protects a body part; forms essential part of the sense organs

Epithelial surfaces: skin, mucosal linings of internal organs

Epithelial tissue: Covers internal and external body surfaces … Types:

  • Mesothelium: tissue covering internal organs and blood vessels
  • Endothelium: covers serous membranes, such as peritoneum

Epitope/antigenic determinant; determines which antigen is attacking the body; part of antigen that is recognized by the immune system, specifically by anitbodies, B-cells, T-cells.

Epizootic: diseases that spread quilckly among animals

Erector muscles: raise feathers for cooling, shaping

Ergot poisoning: fungus in cereal grains

Erythema: redness of skin caused by blood clogging in small blood vessels

Erythrocyte: (avian) red blood cell consisting largely of hemoglobin and carrying nearly all the oxygen containing in the blood; manufactured in bone marrow

Eschar (es’kar): hard crust or scab as from a burn; deep cutaneous slough such as from a thermal burn, corrosive action or decubitus ulcer

Esophagus: connects to crop then travels through bones at top of keel to connect to proventriculus

Esters: chemical combination of an alcohol and acid; fragrant flavors used in foods and perfumes

Etiology: origin or cause of a disease

Euthanasia: causing death humanely and painlessly to end suffering

Eutocia: ease of delivering eggs

Eutrophic (eutrophia): state of good nutrition

Euvolemia normal blood fluid volume Evert: turn out, as eyelid

Eviscerate: remove or expose internal organs, esp after unsuccessful surgical closure of abdomen

Excoriation: injury to surface of body caused by trauma, e.g., scratching, abrasion, chemical or thermal burn; superficial abrasions which remove some of the skin; caused in animals by rubbing or scratching pruritic skin

Excrete: to separate and eliminate from an organ; expel from blood or tissues; waste matter

Excretory urography: radiographic imaging of urinary tract for diagnosis

Excursions: range of movement regularly repeated in performance of a function; e.g., excursion of the jaws in chewing, thoracic movements

Exocrine: secreting through a duct, e.g., exocrine gland

Exocrine pancreatic insufficiency: not enough fluid being secreted through pancreatic duct

Exophthalmus/exophthalmia or proptosis: protrusion or bulging of the eyeball from the orbit due to papilloma or disease, esp hyperthyroidism, or injury, sinus infection, thyroid disease or trauma

Exostosis/exostoses: benign new growth projecting from bone surface and capped with cartilage because of excess calcium forming; Exostoses can cause chronic pain ranging from mild to debilitatingly severe, depending on the shape, size, and location of the lesion. It is most commonly found in places like the ribs, where small bone growths form, but sometimes larger growths can grow on places like the ankles, knees, shoulders, elbows and hips. Very rarely are they on the skull. They normally form on the joints of bones and can grow upwards. For example, if an extra bone formed on the ankle, it might grow up to the shin.

Exotic bird: one that is tropical or non-native to North America

Exotoxin: toxin or poison produced by bacterial microorganism and excreted into its surrounding tissue

Exsanguination: pulling/sucking blood to drain the blood; bleed to death; deprive of blood

Extant: still in existence

Extensor rigidity: muscles contract and straighten the limb, preventing it from relaxing

Exterpated: killed off or destroyed from a certain region, state or country

Extracellular: occurring outside a cell

Extracranial: occurring outside the skull

Extrahepatic: occurring outside the liver

Extraluminal/intraluminal: lighting from without, from within; intraluminal fluid lights up body masses

Extrapair paternity: young in the nest fathered by a bird other than resident male

Extravasation: discharge or escape, as of blood, from a vessel into the tissue

Extrinsic: existing outside the anatomical limits of a part, e.g, certain muscles or nerves

Extrinsic mass: existing on or outside a part

Exudate/exude: matter coming from a part, e.g., nose, uropygial gland; discharge slowly, accumulation of fluid, protein, and cellular debris in a cavity; matter penetrates through vessel walls into adjoining tissue or outside; production of pus or serum coming out slowly, ooze out through small openings, pores, like sweat

Exuviate: cast off, molt

Bird EyeEye: larger than humans’ proportionally and larger compared to skull; take up about 15% of head mass and weight; lighter compared to human skull

Eye crescents: contrasting white crescents seen above and below the eye of the bird

Eye deformity (congenital): incomplete separation of eyelids, narrow eyelids, mostly in lutinos, surgery not usually successful

Eye line: line of feathers just in front of and behind the eyes; extends back from the posterior angle of eye

Eye ring: pale ring of feathers encircling the eye; narrow, not clear from a distance; separates the eye from the face feathers; not all birds have them

Eyebrow: arch of feathers growing overtop the bony arch of each eye, similar to human eyebrow; supercillium or superciliary line

Eyelid: one upper and one lower lid; lower more moveable;

Eye stripe: see “supercilium

Fall molt: aka winter plumage, fall plumage or basic plumage

False negative/positive: diagnostic test reads incorrectly

Fascia: layer of condensed connective tissue which covers, unsheaths, supports, or binds together internal body parts or structures; continuous with other connective tissue structures such as ligaments, tendons, periosteum

Fasciitis: inflammation of fascia

Fat deposits; found in abdomen of birds, not breast; yellowish deposits cranial to vent under the skin; sometimes found cranial to pygostyle

Feather: keratinous structure made of protein and covering body; lightweight and strong, protects skin, enables flight, used to attract mate, waterproofs body, prevents pathogens from entering through skin

Feather numbering: numbering system which assigns a number to each primary feather for identification; primaries are counted from radiale/ulnare (#1) to the alula (#10); secondaries are counted from the manus joint to the humerus, 1-18 

Feather CystFeather cysts: swellings on body wall, wings or tail; caused by feather growing in or under skin instead of out of follicle; genetic or due to injury to feather follicle, malnutrition, parasites, viral or bacterial infections; treatment is surgery to remove feather follicle; most often seen in macaws and canaries

Feather Duster disease: a rare mutation in budgies; impaired growth, short life span; feathers grow in curls without stopping

Feather duster disease


Feather dystrophy:

  • Clinical signs: parakeratosis, hyperkeratosis, feather defects (stress marks), scaliness of apteria, pruritis, persistent feather sheaths
  • Causes:
    • Malnutrition: causes hyperkeratosis, results in feather loss due to hypovitaminosis A and loss of pigmentation, and parakeratosis from pantothenic acid deficiency
    • Iodine deficiency: results in hypothyroidism
    • Heavy endoparasitic infection: retards absorption of nutrients
    • Vitamin deficiencies, esp Vit. B

Feather Follicle: group of cells in the skin from which feathers develop

Feather sheath: thin, cylindrical tube of keratin surrounding and protecting developing feather; breaks open when feather matures to let feather unfurl

Feather structure: Feathers are composed of starch, nucleic acids, protein, and lipids.

Feather tracts: pterylae, areas of skin where follicles lay

Fecal Floatation: test that floats parasite or worm eggs so they can be seen under a microscope; feces mixed with chemical solution, spun in centrifuge, and the fluid lying above the feces at the bottom of the test tube is drawn off, stained, and examined

Fecal SacFecal sac: the sac enclosing the feces of nestling birds; the parent removes it and keeps the nest clean

Fecal smear: feces smeared on slide; determines parasites, bacteria, fungi, protozoa

Feces: solid body waste from intestines

Feet: located at terminal part of legs; most have four toes; hallux (first toe) points backwards, others forward; 2,3, 4 digits counted from inside of the foot out; in parrots, two front toes, two back

Femoral: pertaining to or located in femur/thigh

Fibrin: white, insoluble fibrous protein essential to blood clotting

Fibrinogen: protein in blood plasma that converts to fibrin; fibrin threads form a meshwork for the basis of a blood clot; fibrogen is formed in the liver

Fibroblast: immature fiberproducing cell that is capable of differentiating into a cell that can produce collagen, bone or cartilage

Fibrocartilage: articular, covers joint surfaces of bone; e.g., meniscus: curved fibrous cartilage found in joints, cushions forces applied to joint

Fibrocartilaginous callus: forms between broken bones

Fibroma/fibroid: tumor composed of fully developed connective tissue

Fibronecrotic lesion: lesion covered with thick, yellow membrane composed of exudate and firmly attached to the tissue beneath

Fibrosarcoma: sarcoma (cancer) arising from collagen-produced fibroblasts

Field marks: visible signs on a bird which will allow ease in identification

Filamentous: long and slender; microbiology; very long strand of similar cells joined end-to-end, as in some bacteria and algae

Filarial/Filariasis: parasitic tropical disease; referring to, infected with, transmitted by or caused by thread-like nematodes (roundworms)

Filoplumes: hair-like feathers with no vein and small tuft at top

Fine-needle aspirate: suction applied to hollow needle inserted into tissue; a core of tissue is withdrawn to culture or examine microscopically

First generation: medications developed from an earlier form of medication; developed from original form of the drug; second generation meds are adaptations of the first generation, etc.

First intention (primary union): manner of healing: occurs when surgical incision or cut heals immediately; restoration of tissue continuity occurs directly, without granulation; union of skin edges heal quickly

Fistula: narrow passage or duct formed by disease or injury, as one leading from an abscess to free surface, one cavity to another, or opening made into hollow organ, e.g., eyeball or bladder, for draining; suppurative inflammation; tube-like pasage within body tissues, usually between two internal organs or from organ to body surface; Some created surgically; permits passage of fluids, pus, secretions, or saliva

Flagella: whiplike appendages on certain bacteria and protozoa

Flange (oral): brightly colored enlargements around base of neonate’s beak; extends from corner of mouth and tapers toward tip of beak; supplied with tactile nerve endings; parent feeding young touches flange, mouth springs open, bright colors help parents place food properly

Flank: visible sides of the bird seen below the wings

Fledge: the act of a young bird leaving the nest

Fledging/Feldgling: baby bird out of nest but unable to fly or feed itself without parents; process of leaving nest; premature fledging: baby leaves nest before it is developmentally ready, usually dies

Flight feathers: remiges, rectrices, tertials and secondaries; remiges, long, stiff feathers attached to bones of wing; two groups: primaries and secondaries; involved in propelling and steering; attached directly into periostium (bone); rectrices (tail feathers); body feathers originate in skin

Floaters: birds that do not hold territories or form pair bonds but travel to areas containing territorial birds, waiting to take over territory or nest, copulate with a paired bird

Flocculating agent: substance/chemical capable of penetrating another substance; results in one being suspended in other

Flock: a group of similar birds

Flora: (intestinal) bacteria normally found in intestines

Fluroscope/fluorscopy: instrument with which x-ray images of the body can be viewed directy on the screen; used to monitor motility of GI tract, joint or organ systems in movement

Focal limited to small area or volume

Fomite: a pathogen-contaminated object that can transfer a pathogen from host to another person/animal; e.g., a computer keyboard used by multiple people

Foramen: a natural opening or cavity in a human or animal body, usually one through which blood vessels and nerves pass through bone

Forehead/frontal region: area above eyes and cere

Foreign antigens: antigens unlike the self; autoimmune disease occurs when body becomes intolerant of its own cells

Foreneck: throat, front of neck; jugulum (throat patch)

Fossa: a hollow, pit, or groove in a part of the body such as in a bone

Foveas: particularly sensitive spots in the retina

Fracture: break in a bone caused by trauma, twisting, weakening of bone structure due to disease or injury

Frank blood: bright red blood in stool from hemorrhoid or anal fissures; on surface of stool, not digested; Black, tarry stool: is digested blood

Free radicals: natural byproducts of oxygen metabolism that may contribute to development of chronic diseases, e.g., cancer, heart disease

Friable: readily crumbled, brittle, easily reduced to tiny particles, fragile; e/g., damaged skin

Friction rubs: found upon ascultation; rubbing together of 2 inflamed surfaces, e.g., pruritic friction rubs; in birds, lung and air sac noises and friction rubs could indicate air sacculitis

Frontal shield: An extension running from the upper beak to the forehead

Fulguration: surgical destruction of tissue, e.g., feather cysts

Fundus: the bottom or base of an organ; the part of a hollow organ farthest from the opening; e.g., retina of eye

Fungicide: chemical that kills fungi

Fungus/fungi: low forms of plant life; widespread in nature; unable to form protein and carohydrates; larger than bacterial cells; nucleus and vacuoles can be seen through microscope; major groups are yeasts and molds; infect body, skin, feather follicles; treated with oral and/or topical antifungal

Furcula: fused clavicle or collarbone; aka wishbone; springlike connection between shoulder joints; clavicles fuse ventrally to form furcula; fused at the ends to form a V-shape

Furosemide is a loop diuretic (water pill) that prevents the body from absorbing too much salt, allowing the salt to instead be passed in the urine.

Gaggle: flock of geese or sound given by a goose

Gallinaceous birds: pheasants, chickens, turkeys, waterfowl

Gamete: one or two cells, sperm or ovum, whose union is necessary in sexual reproduction to initate development of new individual; term also used for parasitic organisms

Gametocyte: cell that produces gametes; an oocyte or spermatocyte

Gander: male goose

Ganglion/ganglia: a knot or knotlike mass; general term to designate a group of nerve cell bodies located outside centeral nervous system

Ganglioneuritis: sensory ganglionitis or ganglioneuritis: rare problem in which sensory dorsal root ganglia as well as sensory nerve endings connected to them are damaged; the result of inflammation caused by underlying illnesses; results in spontaneous random movements of limbs and proprioceptive defects; poor prognosis; can be halted if found before irreversible damage occurs

Gape: the mouth lining or margin at the corner where the two mandibles intersect (commissure); also to gape is to open the mouth wide, stretching the commissure. This is done when bird is thirsty or has something in its throat.

Gapeworm: roundworm that lodges in respiratory passages; rare in pet birds; most often seen in exotic galliforms

Gaping: begging behavior of young birds, begins shortly after hatching; widely opened mouth; adult birds can gape for air

Gastric lavage: flush out the crop

Gastroenteritis: inflammation of lining of stomach and intestinal track; symptoms are vomiting and diarrhea

Genetic disorder: inherited, defective genes

Genotypes: group of organisms having the same genetic construction; viruses can have multiple genotypes or mutations Aka viral drift

Genus: level of classification between “species” and “family”

Germinal spot/disk: light-colored site on egg yolk where embryo will eventually develop

Germinative layers: earliest stages of development, deepest layers

Giardia/giardiasis /Giardia lamblia: the parasite causing intestinal infection; a genus of anaerobic flagellated protozoan that colonize and reproduce in small intestines; leads to malabsorption of Vit. E; Oocytes (dropped cysts) eaten by other birds during copraphagia and passed on; exists in filth, causes diarrhea, weight loss, malabsorption deficiency disease.

Symptoms: feather picking, selfmutilation, screaming, cow-pie feces, passing undigested foods, failure to thrive, strong malodor

Gizzard: organ in the digestive tract of birds who eat seeds whole; comparable to ventriculus in psittacine family

Gland: secretes material used elsewhere in the body The only true glands of the integument in birds include the uropygial gland, sebaceous glands of the ear canal that secrete a waxy material, and glands of the vent that secrete mucus.

Glaucoma: increased pressure within the eye, caused by accumulation of fluids; leads to blindness

Glenoid cavity: (pit or socket), a depression in the ventral angle of the scapula for articulation with the humorus

Globoid: global or round shape, having globules

Glubulins: simple proteins that are insoluble in pure water

Glomerulitis: inflammation of nerves or blood vessels of kidney

Glomerulonephritis (GN): aka glomerular nephritis; renal disease; inflammation of glomeruli, or small blood vessels in kidneys

Glomerulophathy: set of diseases affecting the glomeruli of the nephron (kidney)

Glomerulus: area of blood filtering in the kidney

Glottis: opening to windpipe at upper part of trachea, closes during swallowing, allowing the food to pass into the esophagus at base of tongue

Glucocorticoid: hormones produced by adrenal gland to regulate protein, carbohydrates and fat metabolism; glucocorticosteroids stabilize cell membranes as they function in treating allergic reactions

Glucogen: in birds, pancreatic hormone needed for glucose to be used for energy in cells; birds do not produce insulin

Glucogen resistance: blood glucose level remains higher than it should

Glucosamine: substance the body makes and uses to form new cartilage

Glucose: simple sugar in foods, esp fruit; found in blood, major source of energy

Glucosuria/glycosuria: glucose in the urine

Glycogen: storage form of glucose in the body

Going light: losing weight

Goitogens: goiter-producing substances

Gonads: primary sex organs, testes and ovary

Gonydeal spot: reddish spot around the gonydeal expansion on the lower mandible of a gull

Gonys (go’nis): central midline ridge running from the tip of the lower beak back to the anterior end of the head; along the tip of the lower mandible of bird’s bill, at junction of the two joined halves, esp prominent in gulls

Colorful Gorget (neck patch) in a male hummingbirdGorget: area of iridescent feathers found about the head and neck of most male hummingbirds and some females

Gosling: young goose

Guano: bird excrement in the crystalline form of surplus nitrogen known as uric acid

Gout: kidneys malfunction; urates built up in blood and are deposited into joints (articular) and around heart, liver and organs inside body (visceral). Nitrogen is major waste product in urates, give it white, pasty look; when kidneys don’t function well, urates are built up in blood and deposited into joints and around organs;

  • Symptoms: depression, lameness, joint swelling, redness, white nodules in joints
  • Cause: old age, advanced kidney disease, severe dehydration
  • Diagnosed by urine and blood tests
  • Treatment: fluid therapy, electrolyte therapy; allopurinol dissolves urates and aids in excretion; poor prognosis

Graduated: feathers successively shorter from center to outside as in tail and longer from body to alula (wings)

Gram: measure of weight; 28 grams=1 ounce; 454 grams=1 lb

Gram’s stain: method of differential staining of bacteria; gram positive bacteria stains violet, gram negative stains red or pink; staining quality is based on structure of cell wall surrounding the bacteria. This structure of the cell wall influences which antibiotics will kill the bacteria

Granulated tissue: having a grainy texture

Granulation/Granule: division of a hard substance into small particles (granules); the formation in wounds of small, rounded masses of tissue during healing

Granulocyte: any cell containing granules, esp a granular leukocyte

Granuloma: a tumor-like mass or nodule consisting of actively growing capillary buds, fibroblasts and white blood cells; caused by chronic inflammation/infectious disease/invasion of a foreign body, or by healing process of large, gaping wound; marked by formation of granulations associated with infection; can’t be spread to other birds or mammals; it’s an infection

Granulomatous dermatitis: Genetic, chronic disease; immune system phagocytes malfunction, leading to ongoing, severe infection; rare; white cells accumulate in epidermis, esp around follicles;

  • Signs: red/flesh colored palpable small lesions on face; may be scales, pustules, pruitis;
  • Treatment: antibiotics,e.g., metronidazole, erythromycin, doxycycline

Granulomatous tissue in wound healing: new connective tissue and tiny blood vessels that form on the surfaces of a wound during the healing process.

Granulation tissue typically grows from the base of a wound and is able to fill wounds of almost any size.

Granulosa cell tumors: ovarian stromal cell tumor originating in solid mass of granular cells that surrounds ovum in developing follicle; caused by excessive production of estrogen

Greater secondary coverts: feathers overlying the bases of the secondaries; in some birds the primary coverts are completely covered by them

Guild: flock of birds, including different species, which share the same habitat

Gular region: throat or upper foreneck, the area from the lower mandible to the breast bone

Gular sac or pouch:located below lower mandible; allows some species to hold their food; bare skin on throat and base of mandible; in some birds inflates during courtship ritual

Habitat: enviroment in which bird species lives

Half life: time required for the level of substance in body (e.g., drug or toxin) to be reduced by half

Hallux: short hind toe, known as first toe, smaller of the back toes

Hamartoma: benign, tumor-like nodule composed of overgrowth of mature cells and tissues normally present in the affected area but with one element prodominating and growing in a disorganized mass.; benign, focal malformation that resembles a neoplasm; it grows at the same rate as the tissue it is a part of. They occur in many different parts of the body and are most often asymptomatic and undetected unless seen on an image taken for another reason. Disfiguring on skin and damaging to internal structures by compression

  • Vascular hamartoma: dermal tumor mass consisting of blood vessels
  • Parenchymal hamartoma of the lung. The surrounding lung falls away from the well-circumscribed mass, a typical feature of these lesions. The hamartoma shows a variegated yellow and white appearance which corresponds respectively to cholesterol and fat

Hatching: producing young birds through incubation

Hatch year: HY: age designation of a young bird that is still in its first calendar year of life; no matter when it hatched; on Jan. 2 it becomes a second-year bird (SY); bird in its hatch year is a juvenile; After hatch year (AHY) bird is in at least its second calendar year, but whether it is in its second year or older cannot be determined; after second-year, bird known to be at least in its third calendar year or older

Haversian system: small canals through which blood vessels ramify in bone (Ramify: to divide or spread out into branches or branchilike parts)

Hawking: action of catching insects on the wing

Healing by first intention: union or restoration of continuity occurs directly without intervention of granulations.  Healing by fibrous adhesion, without suppuration or formation of granulation tissue. Also called primary adhesion, primary union.  In primary wound healing there is no tissue loss.

A, Incised wound is held together by a blood clot and possibly by sutures or surgical clamps. An inflammatory process begins in adjacent tissue at the moment of injury.

B, After several days, granulation tissue forms as a result of migration of fibroblasts to the area of injury and formation of new capillaries. Epithelial cells at wound margin migrate to clot and seal the wound. Regenerating epithelium covers the wound.

C, Scarring occurs as granulation tissue matures and injured tissue is replaced with connective tissue.

Healing by second intention occurs when there is tissue loss, as in extensive burns and deep ulcers. The healing process is more prolonged than in healing by primary intention because large amounts of dead tissue must be removed and replaced with viable cells.

A, Open area is more extensive; inflammatory reaction is more widespread and tends to become chronic.

B, Healing may occur under a scab formed of dried exudate or dried plasma proteins and dead cells (eschar).

C, Fibroblasts and capillary buds migrate toward center of wound to form granulation tissue, which becomes a translucent red color as capillary network develops. Granulation tissue is fragile and bleeds easily.

D, As granulation tissue matures, marginal epithelial cells migrate and proliferate over connective tissue base to form a scar. Contraction of skin around scar is the result of movement of epithelial cells toward center of wound in an attempt to close the defect. Surrounding skin moves toward center of wound in an effort to close the wound.

Healing by third intention: a method of closing a grossly contaminated wound in which the wound is left open until contamination has been markedly reduced and inflammation has subsided and then is closed by first intention or sutures. Also called delayed primary closure.

Heart: Has 4 chambers as in humans

Heart block: electrical impulses of the heart are not properly conducted from the atria (chambers receiving blood) to the ventricles (chambers pumping blood)

Helminths: parasitic worm, e.g., fluke, nematode, or tapeworm

Helminthiasis: disease of helminth parasites; treated with antihelminthics

Hemagglutination: to stick together (agglutinate) and form clumps; clumping of red blood cells by antibodies directed against antigens or viruses

Hemagglutination Inhibition test: sensitivity test for measuring antibody responses, esp to PBFD; gives birds PBFD status

Hemangiolipoma: benign tumor composed of fat and blood vessels

Hemangioma: benign tumor composed of newly formed blood vessels clustered together, usually found on skin and spleen, caused by leucosis virus in birds; leukemia-like malignant viral disease found in animals, esp poultry

Hemangiosarcoma/angiosarcom a malignant tumor of blood vessels composed of epithelial cells; characterized by extensive matastasism; bleeds profusely if cut; occurs in spleen, liver, skin, heart, muscle Hematemisis: vomiting blood from upper digestive tract

Hematochezia: bloody droppings Hematocrit/PCV:  Packed Cell Volume: lab test to monitor number of red blood cells

Hematology: science dealing with structure of blood and bloodforming tissues, such as bone marrow; studies blood’s function in sickness and health

Hematoma/subdural hemorrhage: bruise; mass of blood within the tissues or abnormal blood clotting; result of trauma to the blood vessels

Hematopoisis: production of red and white blood cells and platelets; occurs mainly in bone marrow

Hematuria: blood in urine, kidney, a liver disease

Hemi-parasites: category of brood parasites who lay eggs in other birds’ nests

Hemianopea/hemianoptic: blindness in half the visual fields; occurs with lesions of optic tracts

Hemochromatosis/Iron Storage disease: genetic disorder; excess accumulation of iron in body; damages organs, esp liver, spleen, pancreas; caused by chronic anemia

Hemodilution: increase in fluid content of blood; leads to lower concentration of formed elements

Hemoglobin: oxygen-carrying pigment of RBC’s that gives them their red color; conveys oxygen to tissues; protein found in RBC’s transports oxygen in the blood

Hemoglobinemia: excessive hemoglobin in blood plasma

Hemoglobinuria: presence of hemoglobin pigment in urine; blood in urine

Hemogram: systemic report of findings of blood test

Hemolysis: rupture of erythrocytes with the release of hemoglobin; causes hemoglobin to be released into the blood plasma

Hemolytic anemia: caused by destruction of RBC’s in the vascular system; caused by transfusion reaction, staph, antibodies in immune system; all attack RBC’s

Hemoptysis: expectoration of blood/blood-stained sputum from bronchi, larynx, trachea, or lungs

Hemorrhage: excessive bleeding; result of injury or clotting abnormalities

Hemosiderosis: focal or general increase in tissue iron storages without associated tissue damage

Hemostasis: stoppage of bleeding;

Hemostat: small surgical instrument used to clamp blood vessels to prevent bleeding

Hen: female adult bird

Hepatic Lipidosis (Fatty Liver disease) Excessive fat accumulation in the liver due to high-fat diet and sedentary lifestyle

Hepatic Peritoneal Cavities: Two paired cavities in liver, ventral and dorsal

Hepatitis: inflammation or infecton of liver

Hepatocytes: liver cells

Hepatoma: liver tumor

Hepatomegaly: enlargement of liver due to disease or heart failure

Hepatopathies: diseases of liver

Hepatotoxicity: poisonous to the liver

Hepatosplenomegaly: enlarged spleen and liver

Hernia: protrusion of an organ through an abnormal opening or other tissues that normally contain it

Heronry: where colonies of herons, egrets and ibises nest as a group

Heterophil: granular leukocyte which reacts serologically with an antigen of another species; predominant leukocyte

High titer vaccine: modified live vaccine; contains higher number of virus particles than “average” vaccine. Can elicit immune system response in young animals that have maternal antibody levels that would prevent them from responding to an average vaccine

Hindcollar: a band seen above the nape and below the crown on the back of a bird’s neck.

Histology: study of microscopic structure of tissues; study of the structure, composition, and function of tissue; deals with minute structure, composition, function of tissues in anatomy;

Histopathology: study of diseases’s effects upon individual cells or group of cells; microscopic study of tissue changes caused by disease

Holocrine: pertaining to a sebaceous gland releasing a secretion that is a product of disintegrating cells; the secretion released by such a gland is called “sebum.”

Homeostasis: stable internal environment; body adjusts to conditions to maintain relatively constant internal environment

Homeotherm/homeothermic: an organism with a stable, independent body temperature; independent of the surrounding environment; animals, including man, who need a constant body temperature.

Homogenous: of uniform quality, composition or structure

Homologous: very similar in position, structure, value or function, sharing common ancestry

Hormone: chemical substance produced by one part of the body which serves as a messenger to or regulator of the processes of another part of the body

Host-specific: virus, bacteria, or parasite that causes disease in only one species or genus

Humor: body fluid, e.g., blood, lymph, bile

Humoral: area of a feather covering the bone near the upper wing or shoulder

Humoral immunity: the result of antibody production by B cells; compare with “cell-mediated immunity.”

Humoral patagium: The fleshy area which connects the elbow to the thorax.

Humorus: large wing bone

Hybrid: offspring of parents of two different species

Hydrocephalus: fluid accumulation in the ventricles (spaces) of the brain; swelling creates pressure on the brain tissues, causes severe damage if untreated

Hydrophilic: affinity for fats or other lipids; promotes absorption of lipids

Hydrophillic dressing: readily absorbs moisture; indicated for use on skin ulcers, surgical incisions, superficial injuries; e.g., burns, lacerations, abrasions; pressure sores; contains Vit A, B6, calcium, magnesium for healing

Hydrophobic: water resistant

Hydrolysis: chemical decomposition; compound is split into other compounds by reacting with water as in

Elemental formulas e.g. Emeraid Hydroscope/hydroscopic: optical instrument composed of mirrors in a tube; used to see objects below water surface

Hydriasis: prolonged dilation of pupil, result of drugs

Hyoid bone: bone in back of bird’s tongue; allows tongue extention

Hyperadrenocorticism: disease caused by hyperactive adrenal cortices; caused by corticotropic adenoma of pituitary or overtreatment with corticosteroids

Hypercalcemia: increased calcium level in blood; results in calcification of soft tissue such as cartilage and overly hardened egg shells

Hypercapnia: excessive carbon dioxide in blood;

Hypocapnia: decreased levels of CO2

Hyperechoic walls/hypochoic: too many or too few sound waves, in radiology

Hyperemia: abnormally large abount of blood in any body part

Hyperesthesia/Hypoesthesia: abnormal sensitivity to sensory stimuli/too little sensitivity

Hyperglycemia/hypoglycemia: higher or lower than normal blood glucose levels

Hyperkalemia: increased level of potassium in blood

Hyperkeratosis/Hyperkeratonic scales: thickening of horny layer of skin, keratin—beak and feet

Hyperparathyroidism: enlarged parathyroid glands from calcium deficiency

Hyperphosphatemia: Elevated blood phosphate levels

Hyperpigmentation: increased dark color of skin caused by pigment “melanin”

Hyperplasia/Hyperplastic: abnormal increase in number of cells within an organ; increased size of organ

Hyperplastic bone marrow: bone marrow with an excessive amount of normal blood cell-producing tissue; leads to anemia; bone marrow unable to supply RBC’s fast enough for normal body requirements

Hyperpnea: deep, rapid respiration, abnormal increase in rate and depth of respirations

Hyperreactive; exaggerated or greater than normal response to a stimulus

Hypersensitive: allergic condition; body overreacts to a certain agent, e.g., bee sting, meds

Hypertension: high blood pressure

Hyperthermia: high body temperature

Hypertonic: body part such as muscle or artery that is under unusually high tension; fluid that has a higher osmotic pressure than another fluid

Hypertrophic osteopathy: excessive growth, abnormal enlargement; manipulation of muscle and bones to promote structural integrity

Hyperuricemia: excessive uric acid in blood

Hypervitaminosis: too much of a vitamin in body

Hyphae: filaments of a fungus, spiral or coiled; when present, there is an invasion of the mucosa by the specific yeast, results in systemic infection

Hyphema: hemorrhage into anterior chamber of eye, caused by perforated corneal wound or head trauma; no treatment; blood reabsorbed in a few days

Hyphosis: abnormal backward curvature of the spine

Hypochromasia: decrease of hemoglobin in RBC’s; they appear abnormally pale

Hypopenae: afterfeathers

Hypoplasia: incomplete or less than normal development of an organ, tissue or cell

Hypopnea: abnormally slow, shallow breathing

Hypoproteinemia: low protein levels in blood

Hyporachis: afterfeather at base of vane

Hypothermia: low body temperatures

Hypovitaminosis: disorders caused by low amounts of vitamins in blood

Hypovitaminosis E: leads to muscular dystrophy, loss of mvt in wings, clamping wings to sides due to muscular fibrosis

Hypervolemic: excessive amount of circulating fluid/plasma in body

Hypovolemic shock: caused by reduced blood volume from massive bleeding or dehydration

Hypoxia/Hypoxemia: inadequate oxygen supply to tissues despite adequate blood supply Iatrogenic: medical disorder caused by physician error

IBA: Important Bird Area

Icterus: jaundice; yellowing of tissues due to abnormal liver function

Idiopathic: disease of unknown origin

Idiopathic prolapse: falling down of organ from original position; unknown cause

Ileum: third and lowest division of small intestine, extends from jejunum to cecum; distal or last portion of the small intestine

Ileus: intestinal obstruction: lack of peristalsis; leads to severe colicky pain and vomiting; caused by disturbances in neural stimulation of bowel

Immature: bird not in adult plumage

Immature plumage: seen on a bird before it reaches adulthood

Immune system: group of lymphatic tissues involved in lymphocyte production, immune responses or both; includes lymphoid organs: thymus, bursa of Fabricus, and spleen; secondary lymphoid organs: lymphatic tissue and nodes; body’s defense system, recognizes infectious agents and works to destroy them

Immune-mediated disease: caused by an unspecified immune reaction; Condition caused by abnormal activity of immune system; body’s IS either overreacts (e.g., IM contact dermatitis) or starts attacking the body itself (e.g., autoimmune hemolytic anemia)

Immune response: production of antibodies or lymphoid cells which challenge an antigen

Immune tolerance: failure to produce antigens against a pathogen; self-antigens are body parts, foreign antigens are outside of body

Immunity: protection for a disease that is afforded by prior exposure to it or vaccination

Immunodeficiency: reduced function of immune system, making it more susceptible to disease; genetic or caused by drugs, radiation, or viruses

Immunogen/immunogenic: substance that causes antibody formation

Immunologic memory: cells created to remember the antigens on a foreign substance after an animal mounts an immune response to it; causes a faster response to the antigen in future

Immunostimulant: compound which stimulates IS to work more effectively to kill bacteria, viruses

Ummunosuppressed: defective immune resonse; inability to produce antibodies against disease or mount an immune response that would normally overcome pathoge

Imperforate: separate by a septum, e.g., human nostrils; Perforate: continuous with other side, e.g., bird’s nares Inappetence: lack of appetite

Incised: cut with a sharp instrument, e.g., scalpel

Inclusion body: a body suspended in the cytoplasm, such as a granule; round bodies in cytoplasm and nucleus of cells, e.g., virus found in cell. An abnormal structure in a cell nucleus or cytoplasm having characteristic staining properties and usually composed of protein, occurring primarily in infectious diseases, especially viral infections

Incubation: the hen resting on eggs, generating heat which causes the eggs to hatch

Incumbent: at same level, resting or leaning on something

Incubation: keeping eggs at proper temperature; providing proper conditions for growth and development, as in bacterial cultures; development of an infectious disease from time of entry of pathogen to appearance of clinical signs

Index case: initial individual whose condition or disease led to investigation of a disease outbreak or hereditary condition

Infarction: localized area of necrosis caused by interruption to blood supply to an organ

Infection: invasion and replication of microorganisms in tissues, causes disease and local inflammation

Infectious agents: organisms that cause infection: viruses, bacteria, fungi, parasites

Infectivity: virulence or strength of pathogenic bacteria

Infiltrate: to penetrate the interstices of tissue; the material deposited by infiltration

Inflammation: tissue reaction to injury, changes it undergoes in healing process; signs are redness, increased temperature, pain swelling, loss of function

Inflammatory response: Immune system response to inflammation

Infraorbital: below the eye

Infraorbital sinus: sinus below/behind the eye

Infundibulum: funnel-like entrance of female’s reproductive tract; egg leaves ovary and enters infundibulum; opening into the oviduct; sperm meet egg there

Infundibular cleft: small slit located behind choanal slit; opening to the middle ears, connected by tube: the pharyngotympanic tube. Middle ear infections cause redness and swelling in cleft

Ingluvies: crop

Innate: permanent genetic characteristic

Inner primaries: feathers closest to body on wing, covered partially by secondaries

Inner secondaries: feathers closest to body

Inner wing: similar to inner arm of human; includes shoulder, secondaries and secondary coverts

Innervate/innervation: to supply with nerves; to stimulate a nerve or an organ to activity

Inoculation: vaccine from killed bacteria

Insoluble carbohydrate: fiber; resists enzymatic digestion in small intestine

Inspissated/inspissate: to condense, become thicker in consistency, cause somethng to thicken by boiling or evaporation

Insufflation/insufflatins/ insufflate: inserting air into an organ or opening in the body

Integument: skin; no sweat glands

Intention: manner of healing, see first, second, third

Intercondylar: between 2 condyles, smooth surface area at end of bone, forming part of joint

Intercostal region: located between ribs

Intergrade: offspring from breeding of two sub-species

Intermediate host: lmmature form of a parasite passes through different host before it can re-enter and infect another animal.

Interramel region/space: fleshy area under mandible, holds tongue and related structures

Interscapular region: between scapulars or shoulder blades

Interstitial: between parts or within spaces of tissue; vascular compartments or organs

Interstitial cystitis: inflammation in wall of urinary bladder

Interstitial infiltrate: cellular infiltrate scattered evenly through the thickness of dermis

Intracellular: within cell or group of cells

Intracytoplasmic: located or occuring within cytoplasm of cell

Intradermal: within skin Intraosseously: into or within bone; medication is sometimes delivered this way

Intraosseous injections: fluids or drugs given into bone using cannula

Intraspecific brood parasite: birds that lay their eggs in nest of same bird species to be raised by other parents

Intraspecific hybrids: When two different races, subspecies, varieties or breeds of the same species are crossed, and an offspring is produced

Intrinsic: pertaining exclusively to a part, as in intrinsic tongue muscles

Intumescence: swollen mass

Intussusception: sliding of a portion of a tubular organ into another portion of it, esp a condition of the bowel, creates swelling leading to obstruction; one part of the intestine “telescopes” into another

Invagination: infalling of one part into another, e.g., intussusception, skin folds; invagination of skin forms feather follicles

Involucrum: covering or sheath that forms around a sequestrum of new bone, as in osteomylelitis

Ipsilateral/contralateral: situated on the same side/opposite side of the body

Iridocyclitis: inflammation of the iris and ciliary body of the eye

Iris: colored part of eye around pupil; does not play a role in vision

Irruptive: certain species of birds may be seen in one year and not in other years.

Ischemic/ischemia: local deficiency of blood supply due to obstruction of blood flow; isch: hold back

Ischiatic nerve: deficiency in blood supply due to vasoconstriction or obstacles to arterial flow; pertains to nerves in caudal or dorsal portion of hip bone, buttock area

Isoflurane anesthesia: volatile, halogenated ether

Isolate: microbio def: to separate a pure strain from a mixed bacterial or fungal culture

Isolation area: special area constructed to prevent spread of contagious diseases

Isotonic solution: one in which body cells can be bathed without net flow of water across the semipermeable cell membrane; has the same salt concentration as cells and blood, used IV for infusing fluids

Jake: young male turkey

Jaundice: elevated bilirubin levels; buildup of bilirubin waste products; bilirubin is yellow, therefore the yellowing of mucous membranes, gums, skin and eyes; result of destruction of large numbers of RBC’s; malfunctioning liver or blocked bile ducts

Jejunum: middle and longest part of small intestine; extends from duodenum to ileum

Joints (articulations) connections between bones; to articulate: to join so that motion between parts is enabled

Joint effusion: fluid escaping from the joint

Jugal: cheek area; jugal arch in birds has same function as zygomatic arch in mammals

Jugulum: ventral part of neck under beak; jugulum and gular region comprise the throat; aka foreneck or throat patch

Juvenile: young bird in its hatch year; plumage seen on a fledgling

Juvenile plumage: feathers on bird after they molt natal down; first true contour feathers

Karyomegaly enlarged nucleus

Keratin: hard protein that forms scales and claws; primary structural component of mature feathers and horny body parts; insoluble in water; strengthens feathers, beaks, claws, bills

Keratinocytes: keratin cells

Keratitis: inflammation of cornea of eye, caused by infection, trauma, allergic reaction

Keratocanthoma: KA, low-grade skin tumor originating from neck of a hair or feather follicle; often seen on sun-exposed skin, on face, forearms and hands

Keratoconjunctivitis sicca: “dry eye” due to inadequate tear production; thick, yellowish discharge from eye.   Also refer to Eye Diseases

Keratoconus: conical protrusion of center of cornea

Keratolytic: soft, loose crusts and scales on skin

Keratoma/keratosis: horny growths on skin; callus; bony deposit formed between and around broken ends of a fractured bone during healing

Keratopathy: corneal inflammmatory disease

Kerfs: shallow grooves cut horizontally below the entrance hole on the interior of the front of a nest box; provide footholds for nestlings and adults as they climb up to the hole

Keryolysis: dissolution of the cell nucleus with loss of affinity for basic stains; usually occurs in necrosis

Ketoacidosis: life-threatening condition in which ketones accumulate in bloodstream and lower pH of the blood

Ketones: result from breakdown of fat for energy.  Ketones are the byproducts of broken down fatty acids in the bodies, too much it in your blood is bad for health.  Ketones are produced when you lose weight or when there is not enough insulin (in birds, glucagon) to break down sugar for energy.

Kettle: congregation of migrating birds of prey seen soaring overhead

Kidney: organ that filters waste liquid resulting from metabolism; subsequently excretes it as urine; also secretes urates—the solid waste of the kidney.

Killed vaccine: disease-causing viruses or bacteria are killed then put into a liquid base as opposed to modified live vaccine and recombinant vaccine

Kinetic: producing motion

Klebsiella: nasty gram-neg. bacteria; treated with Claforan

Koch’s postulates: set of requirements for diagnosis of a disease

Koilin exfoliation: falling off in layers; hollowed

Labile: readily or continually undergoing chemical physical or biological change or breakdown

Lacrimal duct: tear duct

Lamellae: thin scales or plates, as in bones; strainer-type teeth found in the bills of waterfowl for feeding purposes

Lamellate: coarse or fine parallel ridges or plates at cutting edge of beak (tomia)

Larder: areas used by shrikes to store their prey

Larva: worm-like offspring of an insect

Laryngeal mound: a conspicuous mound in the throat at the entrance of the larynx in birds

Laryngopharynx: area below epiglottis opening into larynx and esophagus

LDH: lactic dehydrogenase: enzyme found in liver, muscle, heart; released with damage; used to measure degree of pathological condition

Latent infection: carrier state; animal with infection but without outward signs; dormant stage

Lateral Cantus: outside corner of eye

Laxity: looseness

Leading edge of wing: first area from a frontal position when bird is in flight: shoulder and patagial areas

Leiomyosarcoma: malignant tumor containing smooth muscle cells

Lek: a determined area where multiple male birds put on courtship displays to attract female mates

Lesion: damage to organ or tissue

Lesser secondary coverts: short feathers overlying median secondary coverts on top of wing; first row of feathers on wing; aka marginal coverts

Lethargy: lack of energy, sluggish

Leucism (leucistic): condition that turns feathers pale or white; pigment cells fail to develop properly; results in white patches or completely white animal; whiteness of feathers, but does not have red eyes; caused by reduced pigmentation in the bird’s feathers by recessive allele.  Please refer to Albino / Leucistic / Partial White / Pied Hummingbirds for photos and more information

Leukocytes: white, nucleated blood cells in blood and lymphatic tissue

Leukocyte morphology: structure of the WBC’s; tells how sick the bird is

Leukocytosis: increase in number of WBC’s

Leukopenia: decrease in number of WBC’s

Lichenification: thicking or hardening of skin

Life List: number of wild birds seen by one individual birder

Ligament: band of fibrous connective tissue connecting one bone to another bone

Ligand-gated: permitting or blocking through cell membrane in response to chemical stimules

Lingual nail: stiff, pliable, keratinized cuticle on tip of a bird’s tongue; beta keratin filaments arranged like scutellate scales

Lipase: digestive enzyme produced by pancreas, breaks down fat

Lipemia/hyperlipemia/ Lipemic plasma: excessive amount of lipids in blood

Lipogenesis: cause of fat deposit

Lipogenic: produced or caused by fat

Lipoma: benign tumor composed of mature fat cells

Lipophilic: promotes absorption of fats; combines with fats or dissolves in lipids

Lipoproteins: transport form of hepatic lipids

Liposarcoma: cancerous lipoma; malignant tumor characterized by large anaplastic lipoblasts, sometimes with foci of normal fat cells

Liver: largest abdominal organ; produces enzymes required for digestion and bile to digest fat; detoxifies blood and may be damaged in the process

Liver failure: weakness, wobbly gait, difficulty breathing, swollen flui-filled abdomen, swollen liver, end-stage disease; damaged by cancer, fat infiltration from high-fat diet, cirrhosis from chronic exposure to poisons; x-rays, blood tests identify cause and severity; treatment, usually euthenasia because by the time symptoms occur it’s untreatable

Lobe: round projection or division

Locular/loculium/loculi: small sinus in a bone

Lordosis: abnormally exaggerated forward curvature of the spine

Lore (lores, pl) loral region: the narrow area between the commisure of the beak and the nasal canthus of the eye; area between eye and beak

Lumen: cavity of channel within a tube or tubular organ, such as blood vessesls or intestines; opening in a vessel through which fluid flows; affected by constriction and dilation

Lutino cockatiel syndrome: Baldness on crown, hemophilia (uncontrolled bleeding); increased susceptibility to disease; poor coordination; falls off perch at night, Bruised/bleeding wing tips; abdomen, pectoral muscles prone to trama and failing; many genetic problems. These symptoms were common when the lutino mutation was first developed, but proper breeding practices have resulted in a reduction of these signs.

Lumbosacral plexus: network of nerves innervating the perineum and muscles of the pelvic limb; feeds sciatic nerves of hip in sacral and lumbar areas

Luxation: a fracture; loosening or relaxing, to displace the bones of a joint

Lymph: transparent, pale yellow liquid found in lymphatic vessels; collected from body tissues and returned to the blood via the symphatic system; 95% water, rest is plasma proteins; composed mostly of lymphocytes (WBC’s)

Lymph nodes: part of immune system; small masses of tissue containing WBC’s (lymphcytes); blood is filtered through the lymph node allowing foreign or infectious material to be recognized and destroyed

Lymphocytes: 2nd most important white cell; antibody function; B cells and T cells

Lymphoepithelial system: composed of mucosa associated with lymphatic tissue; mucous covers cellular receptors for bacteria and viruses

Lymphokines: chemicals produced by T-cell lymphocytes; signal macrophages and other phagocytes to destroy foreign invaders

Lymphoma/lymphosarcoma: neoplastic disorder of lymphoid tissue; usually malignant; lymph cancer; proliferation of malignant lymphocytes within solid organs such as lymph nodes, bone marrow, liver, spleen; also eye, skin, GI tract; diffuse, not limited or localized

Lymphopiosis: development of lymphocytes or lymphoid tissue

Lysed cells: cause dissolution or destruction of cells by lysins

Lysin: antibody causing the disintegration of RBC’s or bacterial cells; ear wax a mass of partially lysed cells, traps particles to keep ear canal clear

Lysis:;dissolution or destruction of RBC’s, bacteria or other antigens by specific lysin (antibody) or by action of detergents, thus allowing cell contents to escape.

Macaw “Acne”: Small swellings on face caused by small, ingrown feathers on face and eyelids; surgery releases trapped feathers

Macrorhabdus ornithogaster or Megabacteria/Avian gastric yeast: infects birds with low immunity, have concurrent disease, or poor diet

Macrophages: large WBCs; injest foreign particles and infectious microorganisms by phagocytosis; occuring mostly in connective tissue and bloodstream

Malabsorption syndrome: maldigestion; food not properly digested, nutrients not absorbed

Malaise: discomfort, uneasiness or weakness, indicates infection

Malar region/malars/mustache feathers: bird’s cheek feathers; extend between the ear and the throat

Malar stripe: area below eye and beak, parallel to throat; stripe on sides of chin, stretches downward, brightly colored; whisker, mustache or malar streak

Malnutrition: reduced state of health due to improper/insufficient diet

Mandibular prognathism: mandible projects forward so that maxilla is tucked inside it

Mandibular ramus: prong-like projections from the beak on the posterior side

Mantle: upper surface of back and wings covered with short feathers; back, shoulders, upperwing coverts, and secondaries; especially applied to gulls.

Manus: hand part of the wing; contains alula and major and minor digits (phalanges); portion of the wing that supports the primary feathers

MAOI’s: Monoamine Oxidase Inhibitor: chemicals which inhibit the activity of the monoamine oxidase enzyme family; regulate connections between nerves; treat depression

Margin: border/edge of surgical incision

Marginal coverts/wing lining: soft feathers that form a smooth, featureless surface on the anterior edge of the ventral wing; same as lesser secondary coverts or shoulder; top edge of wing closest to body of bird

Marsupialization: conversion of closed cavity into an open pouch

Mast cell: a leucocyte; part of immune system. When stimulated, they release chemicals that signal either injury or infection and cause an inflammation in the area.  Mast cell produces chemicals (mediators), histamine and heparin.

  • Histamine causes capillary walls to become more permeable, or let substances through.
  • Heparin prevents blood from clotting to allow blood to flow to the area of infection or injury. Mast cells play an important role in allergic reactions because of their 34 ability to produce and release histamine.

Mast cell tumor: most tumors benign; groups of mast cells form nodules, tumors on skin; can become malignant

Mate-guarding: mate follows female to prevent her from breeding with another male; assures he is father of at least of the young in his nest

Maxilla: upper beak/bill of bird

Meatus: opening in a bone or bony structure, like ear or nose

Medial bar: central portion of a feather, especially the primaries

Median surival time: Time at which 50% of animals had died

Mediate: exhibit indirect causation, connection or relation

Medium/media: materials used to culture microorganisms

Medulla: marrow of bones; soft, center of an organ, e.g., kidney or adrenal gland

Medullary: resembling or pertaining to medulla of an organ or medulla oblongata of brian; inner substance of various organs and structures, esp bone marrow, spinal cord or brain

  • medullary cavity cavity of the bone marrow.
  • medullary cord cords of tissue in lymph nodes; may be hyperplastic in cases of chronic localized disease.
  • medullary reticular formation the part of the medulla oblongata which controls the trigeminal, facial, vagal and hypoglossal nerve nuclei.
  • medullary sinus part of the flow system for lymph through lymph nodes; drain into efferent lymphatic vessels at the node hilus. edullary

Medullary bones: store calcium in the female for egg laying; female birds produce a layer of medullary bone tissue when they are laying

Medullary bone density: bone marrow

Medullary bone formation: Controlled by hormones, seen in long wing and leg bones

Medullary hyperostosis: abnormal development of bony tissue in the medulla of an organ (see osteomyelosclerosis)

Medullary sheath: layer of myelin surrounding a medullated nerve fiber

Megabacteria: macrohabdus ornithogaster; gastric yeast; pathogenic, large gram+ rod, megabacteriosis causes weight loss

Melanin: makes feathers dark, associated with increased amounts of keratin, so dark feathers are stronger; most common pigments in feathers; occurs mostly in flight feathers; causes these colors: black, gray, light and dark brown, brick red, dull yellow, tan

Melanism: opposite of albinism; the occurrence of very dark or black-colored birds who ordinarily have light-colored plumages

Melanistic: a surplus of dark feathers on a bird

Melena: black blood in stool; hemorrhage in upper GI tract

Membrane: thin layers of tissue that cover a surface, line a cavity, or divide a space or an organ

Mentation: mental activity or state of mind

Mesenchyme: skin cells of mesodermal (middle dermis) origin; develop into connective tissues, blood, lymphatic and blood vessels

Mesentary: fold in peritoneum which attaches small intestine to abdominal wall;

Metabolic acidosis: blood condition; blood too acidic

Metabolism: chemical process; material is produced maintained and destroyed; energy made available; the chemical processes that take place in the cells and tissues of the body

Metabolic energy: (ME) the net energy available to an animal from a certain food

Metapatagium: the tissue at the base of the patagium.

Metaphysis: wider part at the end of the shaft of a long bone

Metaplasia: transformation of one kind of tissue into another, less undesirable type; e.g., tumor formation; change from normal to abnormal cells

Metritis: inflammation of uterus

Microsurgery: repair of minute structures with aid of microscope and small instruments

Microbe: disease-causing microorganism

Microfilaria/ Microfilaremia: parasite of the blood

Microorganism: single-celled life form; e.g., bacteria, fungi, protozoa, virus

Migration: process of moving from one area to the other; birds migrate to cooler or warmer climates and to follow food sources

Mineralization: minerals laid down within tissue in an abnormal pattern, causes a hardening of tissue

Mineralocorticoids: hormones produced by adrenal gland; regulate sodium, potassium, chloride levels in blood

Miosis: excessive contraction of pupil

Mirror: a white spot or patch seen within the dark areas of the subterminal band on the tip of the primaries; usually in gulls

Mirror band: group of white spots seen in the primaries, usually in gulls

Mirror tongue: continuous row of white tips seen throughout primaries and secondaries

Mites: scaly face; parasites that grow around face and beak; treat with Ivermectin

Mitochondria: parts of cell responsible for provided cell with energy

Mitosis/mitotic: cell division; process that produces genetically identical cells to parent cell

Mobbing: group of birds which swoop to attack predator; give alarm calls

Modified live vaccine: take real, disease-causing virus and alter it in lab to a non-disease-causing virus; compare with “killed vaccine” and “recombinant vaccine.”

Molt: process of shedding and replacing feathers; uses 25% of normal protein requirements, extra Vit. A, amino acids with sulpher, nutruition for energy

Monocytes/monocytosis: white cells associated with chronic disease, esp Psittacosis, Aspergillosis, avian TB; excess number of monocytes in blood

Monogamous: bird species who only have one sexual mate at a time

Monogastrics: single-stomach animals

Monomorphic: sexes indistinguishable from each other in plumage and color

Monophyletic: recognized as one race of birds

Monotypic: bird species which have no known sub-species

Monovalent vaccine: stimulates body to produce protection against only one disease, e.g., a rabies vaccine; compare with “multivalent vaccine.”

Morph: a color variation found within the same species of bird

Mortality: death, causative factors

Motility: movement, e.g., intestinal motility, muscular contractions that move food through GI tract; time it takes food to process and be excreted

Moustachial stripe: a line of different colored feathers from surrounding feathers that resemble a moustache

Murder: a group of crows

Musin: any of a group of mucoproteins found in tissues and secretions; e.g., saliva, stomach lining, skin; viscous when wet and a yellow powder when dry

Mucocutaneous: pertaining to muscous membranes and skin, e.g, eyelid

Mucolitic: pertaining to enzymes that break down mucous

Mucoprotein: protein which yields carbohydrates as well as amino acids in hydrolysis

Mucopurulent: marked by an exudate containing both mucus and pus; due to infection and inflammation; coming from eyes, nose, or any body part

Mucosa: specialized membrane covering various passages and cavities exposed to air; e.g., mouth, nose, inner eyelids; if dry, animal is dehydrated; if pale, animal is anemic or in shock; if yellow, animal is jaundiced due to accumulation of waste products which should have been eliminated by liver, liver disease

Mucous: viscous, protective substance secreted by glands of mucous membrane

Multifocal: arising from more than one form or location

Multilobulated organ: contains many lobules, many small lobes or divisions of lobe, e.g., kidney

Multivalent vaccine: combines two or more components to stimulate body to produce protecton against all components

Muscle petechiation: signs: weakness dazed look, cardiac symptoms, pallor in mucous membranes; requires blood tests; treatments: fluid replacement, vit’s B, D2, K, calcium, antibiotics

Muscle tissue: specialized ability to contract and relax.  Types: skeletal, smooth, cardiac

Mutes: fecal droppings of raptors

Mycobacteria: causes Avian TB; similar to mold when cultured; aerobic; high level of lipid in mycobacterial cell walls makes staining difficult, but it is Grampositive

Mycobacterial conjunctivitis: mycobacteria in conjunctiva of eye.  Also refer to Eye Diseases

Mycoplasma: minute organisms lacking true cell wall, causes respiratory disease, pneumonia, and urinary tract infections

Mycotic/mycosis: fungal disease

Mycotoxins: compound produced as byproducts of molds; poisonous substances emitted by fungi

Mydriasis: excessive dilation of pupils of eye; caused by drug therapy, coma, or injury to eye

Myectomy: surgical removal of all or part of muscle

Myelin sheath on nerve: a segmented fatty lamination composed of myelin that wraps the axons of many nerves in the body. The usual thickness of the myelin sheath is between 200 and 800 μm. Various diseases such as multiple sclerosis can destroy myelin wrappings; The cover that surrounds many nerve cells and helps to increase the speed by which information travels along the nerve .

Myelinated: having a medullary sheath

Myelitis: a disease involving inflammation of the spinal cord; disrupts CNS functions linking the brain and limbs; leads to permanently damaged spinal cord; fever, headaches, neuropathy, pain, loss of feeling, peripheral paresis, loss of bladder control, meningeal signs

Myelodysplasia: bone marrow produces abnormal blood cells Stem cells in bone marrow don’t function normally; instead of producing healthy, mature RBCs, WBCs and platelets, marrow makes cells that are immature and die early; results in cytopenia: low levels of one or more types of blood cells in bloodstream; low levels of blood cells or low blood counts; causes MDS

Myeloid system: spinal cord or marrow

Myelolipoma: rare, beningn tumor of adrenal gland; composed of adipose tissue, lymphocytes and myeloid cells

Myeloma: primary tumor of bone marrow, formed in myelocytes (bone marrow cells) or plasma cells; usually involves several different bones at same time (multiple myelomas)

Myocardial fibrosis: heart muscle scarred from chronic disease

Myocarditis: inflammation or infection of myocardium

Myocardium: middle muscular layer of heart

Myocytes: muscular tissue cell

Myopathy: abnormal condition or disease of muscle

Myoplasty: surgical repair of muscle

Myotomy: surgical incision into muscle

Myxoma/Myxomatosis: soft tumor composed of mucous and primitive connective tissue cells and stroma resembling mesenchyme

Nape: area between the base of the back of the head and the wings

Narial feathers: long feathers at the base of the maxilla and extending anteriorly to partially cover the nostrils; present in some groups, such as the crows.

Naris/nares: nostrils, placed in the cere

Nasal septum: partition or membrane between two cavities or soft masses of tissue; birds lack this in nose

Nasal canthus: inner corner of the eye, closest to nose (see medial canthus)

Nasal fossa: depression in which the bird’s nostrils are located; openings into the nares

Nasopharynx: portion of throat behind nasal cavity and above the soft palate

Nebulization: medication used as a spray, inhaled, for bacterial or fungal respiratory infections, esp upper respiratory; topical, localized treatment of internal air sac and is not dependent on absorption; some meds nephrotoxic, need ones that do not cross through the semi-permeable membranes

Neck: allows bird to move head to increase its visual area without moving body; different species have different lengths which are usually proportional to length of legs; holds cervical vetebrae which are the bones that surround the spinal cord; birds have 11 ato 25 cervical vertebrae; have more vertebrae than humans; depending on the length of the neck; minimum length enough to enable reaching uropygial gland for preening; flexible, moble, strong, forms Scurve, protuding forward in front, above level of crop; holds esophagus, jugular veins and trachea

Necrotic/necrosis: cell death in tissue or organ caused by necrobiosis; pathological death of one or more cells, or of a portion of tissue or organ; results from irreversible damage to nucleus from disease or injury

Nematodes: parasitic round worms

Neonate: newborn bird state, lasts till bird opens its eyes and begins to quill out

Neoplasia/Neoplasm: new, abnormal growth; benign or malignant; tumor growth or formation and growth of new tissue; uncontrolled, more rapid than normal multiplication of cells; progressive; can become benign or malignant tumors

Nephrectasis: enlargment of kidney

Nephritis: inflammation of kidney

Nephrocalcinosis: calcification of kidneys from Hypervitaminosis D

Nephromalacia: abnormal softing of the kidney

Nephron: basic structural and functional unit of the kidney; regulates the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed, and excreting the rest as urine; eliminates wastes from the body, regulates blood volume and blood pressure; controls levels of electrolytes and metabolites, regulates blood pH

Nephropathy: disease of kidneys

Nephroptosis: prolapsed kidney

Nephrosclerosis: abnormal hardening of the kidney

Nephrotoxic: poisonous to kidney cells

Nerve: bundle of fibers that transmits messages (impulses) between the brain or spinal cord and body organs

Nervous tissue: specialized ability to react to stimuli and conduct electrical impulses

Nest cup: depression in the nest to hold the eggs

Neurglia: sustentacular tissue that fills the interstices and supports the essential elements of nervous tissue, esp in brain, spinal cord and ganglia; composed of a network of fine fibrils, stellate cells and radiating fibular processes

Neuroplasticity: nervous system can be shaped or molded, depending on outside environment and biological processes that are responsible for pain

Neurotransmitter: Chemical used as a messenger from one nerve cell to another

Neutroceptor: receptor for stimuli that are neither harmful nor beneficial, neutral

Neutralize: change from acidic or alkaline to a neutral pH

Newcastle Disease: virus of poultry and wild birds; paramyxovirus etiology; attacks GI, respiratory and nervous systems; high susceptibility in psittacines

Niche: ecological role played by a bird species within an animal community

Nictitating MembraneNictitating membrane: between eyelid and cornea; has its own lubricating duct (moisturizing system) equivalent to the human tear duct to clean and protect the eye; third eyelid; vertical, semitransparent fold under the eyelid; closes to protect parent from chick’s beak; protects from sun damage; protects diving birds’ eyes

Nidus: a place in an organism where another organism can live or breed

Nociceptor/nociception: nerve ending that responds selectively to painful stimuli; causes sensation of pain

Node: small mass of tissue in the form of a swelling, knot, or protruberance; can be normal or pathological

Nocturnal: birds which feed at night

Nodular lesions: node-like lesions

Nodule: solid bump or lump in the skin that is over 1/3 inch in diameter

Nomenclature: a system of names

Nominate: the term given to a bird which has the same scientific genus name as the scientific species

Non-breeding plumage/eclipse plumage: more drab plumage seen on birds when not in breeding season

Non-passerines: seabirds, waterfowl, birds of prey and doves  (Also see: Passerines: Perching Birds or Song Birds)

Non-pathogenic: not causing disease; some bacteria, e.g., those living normally in GI tract

Non-union: failure of a bone to heal

Nosocomial: infections contracted from being hospitalized

Nonseptic: a condition not caused by an infection; e.g., septic arthritis is caused by infection with bacteria or yeast or other agent; nonseptic arthritis caused by injury or cancer

Notarium: term for thoracic vertebrae, from shoulder to lower back

Notched: a pointed bite taken out, as in the tail or beak

Noxious stimuli: damaging or potentially damaging stimuli on nervous system

NSAIDS: (Non-steroidal antiinflammatory drugs): agents that reduce inflammation but are not steroids; aspirin, Tylenol, etc

Nuchal collar: distinct feather markings across the nape of the bird’s neck

Nucleated erythrocytes: immature form of red blood cells

Nucleolus/nucleoli: round, divided refractile body in the nucleus of most cells; sythesized RNA

Nutraceutical: broad term for components in food or nutritional supplements; contain substances normally present in the body that aid in proper functioning of body systems

Nystagmus: involuntary, rhythmic movement of both eyes in unison

Obstipation: constipation, intractable, unmanageable, intolerable

Obligate brood parasites: brood parasites who lay eggs in other birds’ nests regularly

Obstruction: complete stoppage or impairment to passage; usually preceded by location, e.g., intestinal obstruction; incomplete is partial obstruction

Obtund: to render dull or blunt

Obtunded: depressed

Obtundent: having the power to dull sensibility or soothe pain; partially anesthetic agent

Obturation: obstruction of an opening or passageway, such as intestinal blockage;

Obtuse: not sharply pointed

Occipital patch : a patch located on the back of the crown; e.g., redpolls

Occlude/occlusion/occluding: to stop up, to block; to cut off or prevent the flow or passage of something such as light or liquid

Occult: disease or condition that is not clinically apparent

Ocular fundus: fundus is place farthest from opening of an organ, e.g., the retina of the eye;

Off-label: medication not FDAapproved; often used by vets

Oglets: beginning of a pinfeather, with keratin sheath

Wing AnatomyOlacronan: elbow joint of bird

Oliguria: little urine output

Omentum: free fold of peritoneum or one connecting or supporting viscera or other abdominal structure

Omphalitis: infection of the umbilicus caused by infection of the yolk by E. Coli or other bacteria; yolks watery or caseous, chicks edematous, high mortaliity in early chicks

Oncogenic: causing tumors, esp related to viruses

Oncotic: like a tumor or mass

Oocyst: sporazoan zygote undergoing sporageous development

Oocyte: type of gametocyte that produces ova (eggs); found in protozoa like giardia

Opaqueness: clouding of normally transparent object

Operculated: covered

Operculum: keratinized plate on the inside of the nostrils (nares); small, round, tan or brownish structure, can be obstructed by rhinoliths; a soft, fleshy structure inside the nostril (naris).

Opioid: Narcotic drug; activity similar to opium

Opisthotonos: spasm in which head and tail are bent backward and body bowed forward

Opportunistic disease: caused by pathogens which take advantage of certain conditions; e.g., bacteria, virus, fungi, protozoa; usually do not cause disease in a healthy host with good immune system

Oral hypoglycemic med:  Oral med which lowers glucose level in blood

Orbital ring: area of bare skin surrounding the bird’s eye

Organ: part of body that performs specific function

Organic matter: animal or vegetable tissues

Organized blood clots; replacement of blood clots with fibrous or granulated tissue

Ornithologist/ornithology: professional who studies birds/study of birds

Oropharynx: part of the pharynx between mouth and glottis (opening at top of pharynx). Contains tongue, glottis, choana, palate, salivary glands, esophagus, opening of pharyngotypanic tubes (ear tubes) and laryngeal mound; exam tells about overall health, indicates malnutrition, Vit. A deficiency, bacterial or yeast infection, middle ear infections;

Disease Signs: choana swollen, papillae blunted or absent, infundibular cleft red, abscesses present, thick, white ropy mucus present, internal papillomas present in GI tract, with lesions in orpharynx; they appear small, pink, wart-like

Osmosis: diffusion of fluids through membranes

Osmolality: ability to be absorbed through membranes or porous partitions, gradual absorption

Osmotic diuretic: compound that increases the amount of urine formed and rids the body of excess fluid by being filtered through the kidney into the urine in concentrated amounts and carrying water with it

Ossicle: single middle ear bone

Ossification: process of bone formation from fibrous tissue; continues until maturity; natural process of forming bone; hardening of soft tissue as a result of impregnation with calcium salts; bony mass or deposit of bony material in body

Osteoblast: bone-forming cell

Osteoblastic tumors: form on elastic bone lesions; metastasized cancer on bone

Osteochondresis: abnormal differentiation or disease of growth cartilage

Osteochondritis: infection of bone and cartilage

Osteoclasism: absorption and destruction of bone tissue

Osteoclasts large multinucleated cell as w/resorption of bone

Osteodystrophy: degenerative condition due to faulty nutrition

Osteology: branch of anatomy dealing with skeleton

Osteolysis: breakdown or decomposition of bone

Osteomalacia: abnormal softening of bone

Osteomyelitis: inflammation and infection of bone

Osteomyelosclerosis: obliteration of bone marrow cavity by small spicules of bone; since long bones are air-filled, cavity is filled with bone particules. The normal bone marrow has few fibers and these are found mainly in association with trabecular bone surfaces and blood vessels

Osteotomy: sugical division of bone, or cutting a piece out to correct a deformity

Otitis: inflammation of ear

Otitis externa: external ear infection

Ototoxic: destructive to the structures of the ear

Otoscope/opthalmoscope: magnifying tool for examination of eyes and ears

Outer primaries: longest feathers on the wing, farthest from body

Outer secondaries: secondary feathers farthest from the body – See Wing Anatomy

Outer tail feathers: farthest from body, fan out the farthest – See Wing Anatomy

Outer wing: encompasses the alula and primary feathers – See Wing Anatomy

Ovariectomy/oophorectomy: removal of ovary; only done in very large birds

Ovary: female gonad, matures and releases egg cells during ovulation; only left ovary is funtional in birds to lighten body for flight; enlarges greatly during breeding season; right one is vestigial

Oviduct (distal): uterus

Ovipary: yolked egg reproduction

Ovum: egg released from ovary

Owlet: young owl

Owling: searching for owls at night by birders

Oximeter: device for measuring oxygen concentration in blood

Oximetry: measurement of oxygen concentration in pulse; device is applied to the skin to measure pulse rates and percent of oxygenated and reduced hemoglobin

Oxygen therapy: uses incubators to moniter heat and humidity; face mask for short term; used to stabilize birds during anemia, shock, dyspnea

Oxidize/oxidation: to combine with oxygen; chemical reaction in which oxygen is added to an element or compound; element loses hydrogen in process

PCV: Packed Cell Volume; percentage of the volume of whole, unclotted blood occupied by RBC’s;

PVC hematocrit: lab test, monitors relative number of RBC’s in blood; blood sample placed in tiny glass tube and spun in a centrifuge; cells heavier than plasma gather at one end of the tube; PCV determined as the % of red cellular portion relative to total amount of blood in the tube; remainder is plasma

Pacheco’s disease: liver disease; sudden death in a few days; signs: depression, ruffled feathers, yellow/green diarrhea, polyuria, polydipsia; caused by herpes virus; no treatment; passed in feces

Pair bond: relationship between male and female bird for nesting purposes, some for life

Palatal processes/palatine: medial or lateral palatine processes contribute to development of the palate and separation of oral and nasal cavities

Palatal slit: caudal half of the palate; in birds it is divided by the median choanal slit

Palatine: of or near the palate

Palmate: webbed front toes, as in ducks

Palpation: to examine with hands/fingers

Palpebral conjunctiva: membrane under eyelid; delicate mucous membrane covering internal part of eyelid is attached to cornea

Palpebritis/blepharitis: inflammation of eyelid

Pamprodactyl: all four toes in front, e.g., swifts

Pancreatic exocrine insufficiency: malabsorption due to insufficient pancreatic enzymes: pancreas not secreting enough enzymes through pancreatic duct; weight loss, bulky, pale droppings

Pancreatitis: infection caused by bacteria, virus, or chlamydia infection: Vit E and selenium insufficientcy; severe, lifethreatening; caused by fatty foods; signs: vomiting and painful abdomen

Pancytopenia: abnormal depression fo all the cellular elements in the blood; caused by depression of activity of immune system (bone marrow, spleen, lymph nodes) due to radiation, injury or poisoning

Panniculus (i): layer of membrane or tissue, esp a subcutaneous layer of fat

Pannicular reflex: quick twitch of back muscle in response to a pinprick in the thoraxolumbar area; determines location of lesion in spinal chord

Panniculiitis: inflammation of subcutaneous fat

Pannus: chronic condition of eye; blood vessels grow across the cornea (clear surface of eye); cornea looks hazy, red; eventually takes on dark pigment; aka chronic superficial keratitis

Panthothenic acid: Vit.B5, deficiency causes feather dystrophy; in meat, vegetables, cereal grains, legumes, eggs and milk; needed for skin health

Papillae: small, nipple-like projections on tongue and found at edges behind choanal slit; others found pointing towards back of throat in the oropharynx; also on uropygial gland

Papilloma/Papillomatosis: warty growth on mucosal tissue,feet, uropygial gland, corners and inside mouth, around beak, wings, eyelids, cloaca, intestines.  Causes cloacal prolapse mostly in macaws and amazons; papillomas extend from orifice; surgery is possible in area without damage to other structures; might go away on their own, but can become internal; benign tumor derived from epithelium; arises from skin conjunctiva, mucous membrane or glandular ducts; can be keratinized, fibrovascular or squamous

Papillomavirus: naked virus, specific to species, even specific to epithelial places on animal; virions stable and easily transmutable (subject to change); found in basophilic intranuclear inclusion bodies

Papule: small, solid, round bump on skin; usually less than 1 cm I diameter; may open when scratched and become crusy and infected;

Parabro: tiny tubes in bird lungs through which air moves in a oneway flow; oxygen and CO2 are exchanged in microscopic capillaries in spaces within parabronchial walls

Parakeratosis: abnormality of horny layer of skin resulting in disturbance of the process of keratinizaiton; cause is dietary deficiency

Paralysis syndrome: loss of motor mvt in a certain part of body; muscles may be flaccid (weak, no tone) or spastic (muscles are tight); wobbly gait, ataxia, lack of coordination, reluctance to walk, lies of floor of cage, abnormal head mvts, mostly in cockatiels; cause is Vit. E and selenium deficiency

Paramyxovirus: causes Newcastle disease

Parasite: organism that feeds upon the tissues of a host organism; ectoparasite or endoparate; subcutaneous parasite penetrates outer body tissues of host and lives there

Parasitemia: presence of parasites in the blood

Parasympathetic nervous system: part of nervous system which stimulates the pancreas to produce digestive enzymes; stimulates many of the smooth muscles in the body, e.g., stomach and intestine; slows heart rate

Paratenic host: intermediate host of a parasite which transfers or transports it from one host to another; e.g., rats carry fleas responsible for disease

Parencentecis: surgical puncture of a cavity for aspiration of a fluid

Parenchyma: essential or functional elements of an organ, as distinguished from its stroma (connective tissue or an organ or framework)

Parenteral: means of administring drug, blood, or nutrients other than by mouth; subcutaneous, intramuscular, interosseus, intravenous, injection

Paresis/paretic: partial motor paralysis; In leg, caused by enlarged kidney putting pressure on ischiatic nerve which goes into leg

Parliament: group of owls

Particulate: small particle

Passerines: formerly known as Passeriformes; songbirds

Passive immunity; produced by providing antibodies or immunologic cells from another source, such as colostrum; compare with active immunity

Patagium/Patagia/patagial: wing membrane, flat fold of skin; structures in areas where wings, legs, tail and neck meet body; these and ventral tail region are common sites for ulcerative dermatitis; elastic fold of skin extending from the shoulder to the carpal joint

Propatagium: elastic triangular fold of skin on the leading edge of the wing; tatoos placed there, surgical sexing done there; stretches from front of elbow to carpus

  • Metapatagium: area at the base of the patagium
  • Postpatagium: tough band of tendinous tissue that envelops and supports the quills of all the wing remiges, from elbow to wingtip.
  • The fleshier humoral patagium connects the elbow to the thorax.

Patagial marks: feathers associated with the area of wing joints

Patagial tags: bird bands attached to the propatagial area of the wing of a soaring bird that can be seen from the ground

Patency: affording free pasage, as in air-sac tube; clears for passage of air

Pathogen/pathogenic: organism that causes disease: bacteria, parasite (protozoa), virus, fungus; any microbiological cell containing sufficient genetic information is capable of producing disease

Pathogenic organisms: capable of causing disease, either directly by infecting or indirectly by producing a toxin that causes illness

Pathogenesis: production and development of disease

Pathognomonic: distinctively or decisively characteristic of a particular disease; a pathognomonic symptom: specifically characteristic sign on which a diagnoisis is made; used to describe a symptom or sign that indicates almost beyond doubt the correct diagnosis of a disease

Pathologist: examines the changes in body tissues and organs caused by disease

Pathology/pathological: study of the nature, cause and development of abnormal conditions and disease; involves organ or tissue changes in structure and function; condition produced by disease

Pathonomia/pathonomic: science of the laws of a disease

Pathophysiology: study of changes in function caused by disease

Pathotype: ascertains the kind of blood or tissue sample of a disease

PCR: Polymerase Chain Reaction: molecular diagnostic test: amplifies a fragment of DNA from minute quantities of DNA source material

PCV: packed cell volume: the percentage of the volume of whole, unclotted blood occupied by the erythrocytes; high PCV indicates dehydration

Peacock: male peafowl

Pectoralis muscles: largest and most powerful muscles in flying bird’s body; contractions power the wings’ downstrokes

Pedicle: foot-like, stem-like narrow basal part or structure, such as a narrow strip by which a graft of tissue remains attached to the donor site; e.g., the uropygial gland absess hanging down from the gland, or xanthoma hanging down from the wing

Pedunculated: having a peduncle or stalk

Peeps: general term for shorebirds

Pelagic: ocean-going birds that are seldom seen from land

Pen: female swan

Penicillinase: enzyme produced by some bacteria which inactivates certain types of penicillin, thus making the bacteria resistant to them.

Penile: a nest that is suspended between two forks of a limb with nothing supporting it from below

Penna: contour feather

Pennaceous: having the texture of a penna as opposed to a down feather

Peracute: extremely acute, of only a few hours’ duration

Percutaneous: medicine that is administered or absorbed through the skin

Perforation: formation of a hole in an organ, tissue or tube; usually a consequence of disease

Perfuse/perfusion: to force fluid through tissue or organ by way of blood vessels; to permeate or spread throughout the body; liquid circulating through blood vessels or other channels within the body

Pericardial effusion: escape of fluid around heart

Pericardium: double-walled membrane surrounding the heart;  Two layers: fibrous and serous; fibrous is tough external layer, serous is inner layer, thin, moist, transparent.  Layers of the pericardium:

  • Epicardium: external layer, serous
  • Myocardium: middle, thickest layer, actual heart muscle
  • Endocardium: inner layer, lines chambers and valves

Perietal peritoneum: outer layer of peritoneam

Periosteal proliferation: reproduction or multiplication of similar cells; periosteal cells multiply too much; abnormal growth or increase in number of cells, creates swelling

Periostitis: inflammation of periosteum

Periostium: normal investment of bone, consisting of dense,tough, fibrous outer layer to which muscles attach, and a deeper, more delicate, succulant osteogenic inner layer capable of forming bone; a specialized connective tissue covering all bones of the body and possessing bone-forming potentialities; is a point of attachment for certain muscles, tendons and ligaments; the connective tissues fuse with the fibrous layers of the periosteum

Periportal: periportal zone is nearest to the entering vascular supply and receives the most oxygenated blood; near the portal vein of the liver

Periportal fibrosis: lesions in the periportal area of liver

Peristalsis: progressive waves and contractions and relaxations of the tubular muscular system, esp the alimentary canal; contents forced through GI system

Peritoneum: membrane lining the wall of the abdominal and pelvic cavities and covering some organs in this area

Peritonitis: inflammation of the peritoneum

Perivascular: around a blood vessel

Perivascular dermatitis: inflammatory dermatosis in which the reaction is centered around superficial or deep dermal blood vessels

Perosis: disease of young birds caused by nutritional deficiency; excess calcium and deficiency of choline and magnesium: deformed leg bones above and below the joint, enlarged tibiotarsal joint, results in crippling and death

Petechia/petechiation: A small purplish spot on a body surface, such as the skin or a mucous membrane, caused by a minute hemorrhage and often seen in typhus.

Petinate: comb-like teeth that the claws on some deep-water waders are furnished with

Phacoemulsification: removal of cataract using ultrasound to disintegrate the cataract; then it is aspirated and removed; uses dorzolamide topical med

Phacolysis: dissoluton of eye’s crystalline lens

Phagocyte: WBC; absorbs foreign bodies in blood stream; “eats” damaged cells and foreign substances such as virus or bacteria; macrophage is a type of phagocyte

Phagocytic: any cell that ingests/destroys foreign particles

Phagocytosis: act of destroying the foreign particles

Phalanx: bones of a digit

Pharyngo-tympanic tubes: eutachian tubes in ears

Pharynx: in throat; air passes through nasal cavity to the pharynx; common passageway for the upper respiratory and GI tracts

Philopatry:birds migrating back to the same region where they were born

Pheromone: chemical secreted by an animal and sensed by another of same species; causes reproductive behavior in that animal

Phlogistic: inflammation and fevers;

Anti-phlogistic: works against inflammation and fevers

Photoperiod: number of hours of light per 24-hour period

Photosensitivity: skin reacts abnormally to light, esp ultraviolet or sunlight; caused by interaction of light with certain chemicals in the skin, antibiotics, hormones, or toxins

Phylogeny: evolutionary history of any plant or animal species

Physiology: study of how the body functions

Piebald: two colors of feathers

Pileum: entire top of the head, including the forehead, crown, and occipital reagions

Piloerection: erection of feathers using erector muscles and depressor muscles; plays a part in thermoregulation; bird fluffs up in cold weather to trap body heat

Pin feather: newly developing blood feather emerging from the skin

Pinna/pinnae: feather, wing, or wing-like part; elongated feathers projecting from the upper body area, generally neck or head

Pipping: process of chick puncturing a small hole in shell at hatching

Piriform: pear-shaped

Pishing: sound generated by forcing air through lips to attract birds

Pityrosporum/Malassezia: inflammatory skin disorder that typically manifests itself as a pruritic, follicular papulopustular eruption distributed on upper trunk; affects young to middle-aged adults; yeast pathogen; linked to seborrheic dermatitis, folliculitis, pityriasis and atopic dermatitis; lesions are chronic, erythematous, pruritic papules and pustules; etiology: plugging of the follicle followed by overgrowth of yeast that thrives in the sebaceous environment;

Plasma: fluid portion of the blood in which red and white blood cells and thrombocytes are suspended

Plasmid: small, independent circle of DNA

Platelets: cellular components found in the blood which help clots to form; In the body, microscopically small vessels often break in normal living; platelets and fibrinogen protein “plug” the break in the vessel and prevent blood from leaking out

Pleomorphic/pleomorphism: having more than one shape or form

Plexus/plexi: a network or tangle of nerves or veins

Plumage: bird’s entire feather coat; set of feathers produced by a molt

Plumbism: lead poisoning

Plume: down feather

Plumulaceous: have the texture of a down feather

Plumy: having plumes or feathers

Pneumatic bones: hollow, no marrow, allows bird to be light enough for flight; long bones of wings and legs are air-filled (humerus, femur) as well as pelvic bones, some ribs, most vetebrae, some in head; all have large, airfilled medullary canals that are involved with the respiratory cycle during flight; these bones have a wide medulla (central cavity) and thin cortex (outer wall)

Pneumothorax: entry of air into the pleural cavity enough to cause collapse and resp. embarrassment; the presence of air or gas in the pleural cavity surrounding the lungs, causing pain and difficulty in breathing.  Pneumothorax can occur spontaneously because of accidental rupture or perforation of the pleura

Pododermatitis or bumblefoot; wounds on bottom of feet caused by rough or dirty perches, obesity, hypothyroidism (lack of iodine), Vit. E, A, or calcium deficiencies, stress, staph, trauma to foot, e.g., abrasion, puncture which allows entry of microorganismas and infections; deep infections spreads to tendons and joints, leads to septic necrosis of bone

Podotheca: non-feathered parts of legs

Poikilocytes: abnormally shaped erythrocytes

Pollex: thumb of the first digit of the wing, the alula

Polyandrous: female birds that have more than one mate

Polyarthritis: involves two or more joints

Polychromasia or polychromatophilia: variation in hemoglobin content of erythrocytes

Polycythemia: abnormally high number of circulating red blood cells

Polydactylism: additional digits on toes, hereditary

Polyderma: infection of the skin

Polydipsia: excessive thirst

Polyfolliculitis: more than one feather emerging from a single follicle; possible viral etiology; alternate explanation: the feather splits as it emerges.

Polygynandry: a certain bird species which pairs up to more than one mate. Extra-group or individual mate

Polygynous: group in which males and females have more than one mate

Polymorphic: some species of birds have different colors

Polyomavirus: in young birds; enlarged abdomen, crop stasis, poor motility, subdermal hematomas, death in 2-3 days. In older birds, abnormal rectrices and remiges, weight loss, poor growth; no treatment, vaccination available

Polyostotic hyperostosis: abnormal development of bone tissue; radiographic evidence suggestive of hyperestrogenism that appears as calcification of the medullary space of the long bones, esp femur and humerus

Polyp: a small growth from mucous membranes such as those lining the nasal cavity and intestinal tract

Polyphasia: excessive eating or swallowing

Polyphyletic: derived or descended from several groups of ancestors

Polyuria: formation and excretion of high volume of urine due to diabetes, kidney disease or other disorder

Porphyrins: pigments related to hemoglobin and bile pigments formed in the liver; produce these colors: brown, bright red, greens, red-brown

Portal circulation: circulation of blood from digestive tract and spleen to the liver via the portal vein, and subsequently, out of the liver via the hepatic vein.

Postnuptial: bird that has one molt per year

Postocular spot: distinctly colored spot located behind the bird’s eye

Postocular stripe: a distinctly colored stripe located behind the bird’s eye

Potable: water that is free of pollutants and suitable to drink

Postpatagium: tough band of tendinous tissue that envelops and supports the quills of all the wing remiges, from elbow to wingtip (see Wing Anatomy).

Poult: young game bird

Pox virus: affects mostly young birds; virus can live on fomites for 2 years; causes pustules in or around eyes, lesions on skin and in mouth

  • Skin: Dry Pox; red, oozing sores becoming large and scabby, bacteria and fungi enter to become secondary infections
  • Wet Pox: gray/brown accumulations of cheesy pus in mouth, throat, windpipe; if pus removed, leads to bleeding, can’t swallow or breathe
  • Septicemia Pox: sudden onset of sleeping, ruffled feathers, heavy breathing; death within 3 days
  • Pathology: lungs hemorrhage, fatty liver, inflammation of small intestines, rarely seen in psittacines

Prebasic molt: the molt by which most birds replace all of their feathers, usually occurring annually after the breeding season.

Precocial: birds that hatch in a relatively developed state; have down feathers and open eyes; able to walk, swim, eat on their own

Precursor: substance from which another, more active or mature substance, is formed

Preening: feather maintenance: bird grasps a feather near the base, nibbles along the shaft toward the tip with a quivering motion; this cleans and smoothes the feather; uses oil from uropygial gland and spreads it on the feathers as it preens

Premaxilla: bone which bears the upper beak, supports the maxilla

Prepatent period: early days of infection; the period between infection of the host and the earliest time at which the causative agent can be recovered from the patient or, in the case of parasites, eggs or larvae can be recovered from feces, urine or blood. It is usually shorter than the incubation period but may be longer in some parasitic infestations

Present: how a disease appears as symptoms Prevaricate: walk crookedly, knock-kneed; to be undecided and waver back and forth

Primaries: 9-10 or more outermost flight feathers, attached to the manus of wing

Primary coverts: short feathers that cover and protect the primary flight feathers

Primary and Secondary Feather numbering: numbering system which assigns a number to each primary feather for identification; primaries are counted from radiale/ulnare (#1) to the alula (#10); secondaries are counted from the manus joint to the humerus, 1-18

Primary projections: projection of the primaries beyond the tertials as seen from the side of a standing bird

Probang: long, slender, elastic rod with a sponge or ball at the end used to remove foreign bodies from the esophagus or larynx; also used to introduce medication

Proctodeum/proctodea: another name for bottom level of cloaca; carries cloacal burse and proctodeal glands; holds phallic structure in male; the 3 chambers (urodeum, copradeum) make up the cloaca, divided by mucosal folds

Prognathia: abnormal protrusion of lower mandible

Prognathism or “Parrot Beak:” Mandibular prognathism occurs when the tip of the rhinotheca (upper beak) rests on or inside the gnatotheca (lower beak); most commonly seen in cockatoos; causes may include genetics, improper incubation, and handfeeding techniques. It is rarely seen in parent- raised birds. It is thought that when parent birds hook onto the chick’s rhinotheca during feeding, they help to promote the normal development of the chick’s beak; treatment varies with the severity of the condition and the age of the bird. For some chicks, applying finger pressure several times daily may help, as will using a piece of gauze to apply traction to the upper beak during feeding. In an older bird, in which the beak has calcified, treatment generally involves the placement of an acrylic appliance on the beak. (Drs. Foster and Smith: Pet Education) e.cfm?c=15+1829&aid=2752 

Prokinesis: increase in size of gape

Prokinetic: process of driving or propelling, stimulating movement or motility

Prokinetic drugs: enhance GI motility by increasing the frequency of contractions in the small intestine or making them stronger, but without disrupting their rhythm; new class of drugs for treating constipation, gas, bloating; enhance the passage of intraluminal contents of GI tract

Prolapse: falling down or slipping ouf ot place of an organ from its original position; protrusion of viscera through opening; downward displacement of organ.  Also see Prolapsed Cloaca

Proliferate/Proliferative: to grow or increase in numbers; rapid or repeated production of new parts (cells) by rapid succession of cell division

Proliferative granulomatous lesion: growing mass of necrotic granules or debris resulting in a lesion; rhinoliths become lesions which become infected with microorganisms

Promiscuous: bird groups who join together on for mating purposes

Propatagium: elastic triangular fold of skin on the leading edge of the wing; tatoos placed there and surgical sexing done there; stretches from front of elbows to carpus

Prophylactic: preventive treatment

Proprioceptive: a receptor located in subcutaneous tissues, as muscles, tendons and joints, that responds to stimuli produced within the body; pertains to proprioceptors, the stimuli acting upon them or the nerve impulses initiated by them

Proprioception: perception governed by proprioceptors, as awareness of the position of one’s own body; the perception of stimuli produced within the organism

Proprioceptor: a sensory receptor located deep in the tissues (e.g., heart muscle, skeletal muscle, tendons, GI wall or sinus) that functions in proprioceptive response to changes in physical or chemical conditions within the body; any of the sensory nerve endings that give information concerning movement and position of the body; they occur in muscles, tendons and the labyrinth (inner ear)

Proptosis: forward displacement or bulging of the eye, exophthalmos

Prosthesis: artificial substitue for a missing body part

Protease: enzyme which breaks down protein

Proteins: complex molecules composed of strings of amino acids; main building blocks of all living organisms; also act as enzymes assisting chemical reactions

Protocol: plan for a course of treatment or scientific experiment

Protoplasm: term no longer used in scientific context; a semifluid, viscous, translucent colloid; the essential living matter of all animal and plant cells; it consists largely of water, proteins, lipids, carbohydrates and inorganic salts, and is differentiated into nucleoplasm and cytoplasm

Protoporphyrin: a porphyrin whose iron complex unites with proteins to form hemoglobin

Protozoa: one-celled animals that often cause disease; e.g., coccidia, Giardia

Proventriculous: upper, gastric stomach; secretes enzymes that break down food

PDD: Proventricular Dilatiation Disease: Bornavirus etiology, causes inflammation of nerves in the brain and GI tract; ultimately results in dilation of digestive organs, poor digestive function, wasting and death; no cure or vaccine;

Celebrex treatment. See /proventriculardilatationdisease

Pruritis/pruritic/prurigo: itching skin

Pseudomonas: (sudom’anus) rodshaped bacteria, pathogenic for plants and animals, gram neg.

Psylium: dietary fiber, mild laxative; plant with edible seeds

Psittacine Beak and Feather Disease (PBFD, Circovirus); mostly in young birds, abnormal feather growth, feather loss, shiny beak from lack of powder down, dusty feathers, feather color changes, infectious, respiratory symptoms, conjunctivitis, diarrhea, abnormal urates, slow onset, weight loss, listlessness, loss of rectrices and remiges, twisted deformed feathers; beak rots, immune system compormised; slow death, cockatoos mostly

Psittacine Pruritic

Polyfolliculosis: self-mutilation, itching on rump, neck, shoulders, intense picking to ulcerated areas, feather follicles appear to produce more than one feather due to damaged feather emerging, feathers twisted, deformed or under skin; no treatment successful, no cure

Psittacosis titer: test for Chlamydia psittaci which causes psittacosis.  Also refer to Feather Disorders.

Psychogenic: of mental origin

Pterygoid: shaped like a wing

Pterygoid bone: small skull bone that articulates with the sphenoid bone

Pteryla/pterylae: feather follicle tracks or rows

Pterylosis: pattern of feather distribution, includes pterylae and apteria

Ptosis: prolapse of an organ or part, paralytic drooping of upper eyelid

Pulmonary arteris: large vessels leading from heart to lungs

Pulmonary edema: fluid accumulation in lungs

Pulmonary emboli/embolism: bood clot that travels to the blood 46 vessels in the lung and obstructs them

Pulse: edible seeds of luguminous crops, e.g., beans and peas

Punctured crop or esophagus: A severe puncture wound in a baby bird caused by the wrong utensils when hand-feeding, the bird lunging at the syringe, the parents feeding too quickly and aggressively. Food may migrate under the skin or travel to the puncture wound. Signs are inflammation and swelling around the crop and an empty crop.

Pupil: dark, circular, hollow eye passage through which light enters

Purulent: having to do with pus

Pustule: small elevated area on the skin filled with pus; collects on epidermis or in the dermis; frequently forms in sweat glands or feather follicles; a pimple full of pus

Pygidium: fused bones making up the tail of the bird (pygostyle)

Pygostyle: tailbone; end-most bone of spinal column; holds the rectrices; if damaged, male may not be able to copulate successfully with hen

Pylorus: opening at distal end of stomach leading to duodenum; a splincter muscle which opens and closes as needed to allow food to go into intestines

Pyoderma: infection of the skin; usually result of bacterial invasion; inflammatory skin disease caused by pus-forming microorganisms and marked by supperative lesions; often caused by staph

Pyometra: pus in uterine cavity

Pyriform: pear or egg-shaped

Pyuria: pus in urine

Quarantine area: holding area of isolation for newly arrived birds

Quill: stem of feather inbedded in flesh; stout, horny, cylindrical center of a feather

Race: same a sub-species

Rachis: central shaft of feather; bar running through a feather forming the quill

Radiale: Wrist joint between the radius and ulna bones and manus or carpometacarpus

Radiculopathy: refers to a set of conditions in which one or more nerves are affected and do not work properly; a neuropathy; results in pain, weakness, numbness, difficulty controlling specific muscles

Radiocarpal joint: joins the radius and carpals; the wrist

Radiograph: x-ray

Radiolucent: penetrable by electromagnetic radiation

Radio-ulna: bone in wing

Ramify: to divide or spread out into branches or branchlike parts; extend into subdivisions

Ramus: the peaks in the front of the lower mandible; branch of a nerve, vein or artery

Range map: land images depicting the breeding area, migration route and winter ground of a species

Raptor: bird of prey

Reabsorption/resorption: absorbing again, to take up; the lysis and assimilation of a substance; e.g., bone or fetus; takes matter back into body

Reagent: a substance used to produce a chemical reaction so as to detect, measure or produce another substance; e.g., adding vinegar to baking soda creates foam-forming carbon dioxide and salt; the two react to form CO2 and Sodium acetate (salt)

Recombinant: new cell or indiviual that derives some of its genetic material from one parent and some from another; genetically different individual

Recombinant vaccine: certain antigens on viruses and bacteria are better at stimulating an antibody response; the genes for these antigens can be isolated and made to produce large quantities of the antigens they code for; a recombinant vaccine contains these antigens, not the whole organism; compare with “modified live vaccine” and “killed vaccine”

Recrudescence: recurrence of clinical signs after a temporary abatement; relapse occuring after days, weeks, or months

Rectrix/rectrices: tail feathers; always paired, one central one with 6 pairs; have coverts that lie over and under rectrices

Recumbent crest: crest that curves backwards and lies flat against the head

Recumbent position or recumbency: lying down/ resting;

  • Dorsal R.: lying on the back
  • Ventral R.: (sternal) lying on the belly 
  • Left lateral R. lying on left side
  • Right lateral R. lying on the right side

Recursive crest: one that curves forward, as in the cockatiel

Recurved: curved upward toward tip

Red count: PCV measurments of red cells to serum after spinning down; measures anemia vs. normal red count

Refractory: resisting ordinary methods of treatment

Regulation: using glucogen to maintain blood glucose level of an bird within the acceptable range

Regurgitation: bringing up partially digested food from crop back into mouth and out

Remix/remiges: large flight feathers on wings

Renal capsule: enclosed structure; fatty, cartilaginous or fibrous structure enclosing an organ or part; renal capsule means kidney is enclosed

Renal failure: inability of kidneys to function; acute or chronic

Renal infarction: obstruction of blood flow to kidneys

Renal insufficiency: decreased ability of the kidneys to rid the body of wastes

Reovirus: causes hepatitis

Resistance: describes bacteria which have mutated or changed; no longer affected by an antibiotic that previously killed them or slowed their growth

Respiratory system: used for breathing and cooling; no sweat glands; birds pant to expel excess heat and stabilize body temps

Retained feather’s blood supply: blood stays in the calamus as feather pulp instead of nourishing growing feather

Retained feather sheath: heavily keritanized around calamus instead of surrounding growing feather

Reticulate scales: small, net-like scales (tarsus) covered with a network pattern; marked with lines, composed of alpha-keratin

Reticulocyte: immature RBC that contains a network of fibers of ribosomal RNA (cluster of proteins)

Reticulum: structured part of protoplasm

Retina: rear, interior surface of eyeball; contains nerve cells (rods and cones); rods sensitive to light and cones to color; retina receives the light and color and converts them into nerve impulses which to to the brain

Retinaculum: structure that holds an organ or tissue in place, such as a ligament

Retinol: vit A Retrobulbar: behind the eyeball

Retroperitoneal: superficial to the peritoneum

Rhampotheca: horny covering of entire beak; bones of the beak are covered with a thick, modified integument, entirely on the outside and partly in the lining of the mouth; this is called the rhamphotheca; hard and heavily cornified in most birds, yet flexible in the flexion zone of the maxilla;

  • Maxillary rhamphotheca or rhinotheca: upper mandible, holds cere and nares

Mandibular rhamphtheca or gnathotheca: lower mandible

Rhinolith: a mass formed just inside the nares from desiccated secretions or debris; may cause physical obstruction to proper breathing, disfigues the nares

Rhinorrhea: excessive exudation from nose

Rictal: refers to corners of the mouth

Rictal brisles: short, stiff feathers near the beak; serve a tactile, sensory function

Rictus: base of the beak where the mandibles join; aka gape, commissure; gape is mouth wide open

Ringer’s solution: tissuesustaining fluid; a solution of inorganic salts used to sustain cells, tissues, or ogans outside the body

Rookery: place where large numbers of birds come together to nest and roost.

Roost: resting site used by birds

Rostrum: beak or bill

Rump: area between upper tail coverts and back of bird; has shorter feathers of same color as body

Salmonella: bacteria causing systemic, intestinal and liver disease; zoonotic

Sacculitis: infection of the saccula: smaller of 2 sacs in the membrane labyrinth of the inner ear

Safronine: purplish-red color

Saline: solution of salt (sodium chloride) and sterile water; contains same proportions of these components as does the blood, .9% salt and water

Salivary glands: in roof of mouth and floor of mouth and in tongue

Salpingectomy/ salpingohysterectomy: excision of the salpinx (uterus)

Salpingitis: inflammation of salpinx

Salpinx/salpinges: oviduct or uterus; trumpet-like tube as in fallopian tube

Salt gland (aka sweat gland) a gland, located in the head of seabirds that secretes into the nasal passages the excess salt imbibed or ingested

Sarcocytosis: parasitic disease, usually of food animals

Sarcoma: type of cancer that starts in bone or muscle; tumors made of cancerous bone, cartilage, fat, muscle, vascular, or hematopoitic tissues; different types named after specific tissues they affect; e.g., fibrosarcoma is in fibrous connective tissue

Scale: accumulation of loose fragments of the top layer of skin

Scapulars: short feathers in the area where back and wings join; seen at top of bird’s wing (please refer to Wing Anatomy)

Scissors beak: a lateral deviation of the rhinotheca.  It is a developmental abnormality that occurs most commonly in cockatoos and macaws.

  • It is thought to be caused by improper temperature during artificial incubation, genetics, or incorrect feeding techniques. Other possible causes include calcium deficiency, trauma, or a viral or mycobacterial infection.
  • Treatment varies with the severity of the problem and the age of the bird. In young birds with mild deviations, simply applying finger pressure to the appropriate side of the beak for several minutes 2-3 times daily may correct the problem. In older birds, or those with more severe deviations, an avian veterinarian may need to perform surgery and apply a type of acrylic prosthesis (splint) to correct the abnormal growth. . (Drs. Foster and Smith: Pet Education)

Scleral ossicles: bone within the sclera of the eye

Sclerification: production in the skin of many small superficial scratches or punctures, as for introduction of vaccine

Sclerosis: hardening of tissue, result of chronic inflammation

Scutellate/scuttelation (skootelate): a scaly covering on the bird’s foot; having large, bony plates; large scales on the tops of toes of pigeons and other similar birds

Scutellation pattern: the scale pattern on the feet

Sebaceous: relating to or producing a waxy, yellowish, bodyoil secretion, sebum

Sebaceous adenitis: inflammation of a sebaceous gland

Sebaceous glands: small, oilproducing glands in ear canal and uropygium. Releases fatty substance, sebum. E.g., uropygial gland

  • Exocrine s.g.: secrete chemical substances into ducts that lead out of body or to another organ, e.g., sebaceous glands
  • Endocrine s.g.: secrete their substances directly into bloodstream; these are ductless

Sebum: semifluid secretion of the sebaceous glands, consists chiefly of fat, keratin, cellular material, and dead skin cells. An oily substance that lubricates the feathers and skin and gives some protection against bacteria

Secondary flight feathers: attached to ulna, used for lift in flight

Secondary infection: infection which occurs because the tissue and its natural defenses have been damaged by another condition

Secondary response: the faster and greater immune response produced by an animal who has previously encountered that specific antigen; memory cells are responsible for this more efficient response; aka “anamnestic response.”

Second generation: medications developed from an earlier form of the med; first generation meds were developed from the original form of the drug; successive generations based on the one previous to them

Second intention: (secondary union): a manner or process of healing; occurs when a gaping wound fills with granulated tissue and is then covered from the sides with epithelium; wound repair following tissue loss, as in ulceraton or open wound; granulation bridges the gap between the edges

Secrete: to discharge or empty a substance into the bloodstream or a cavity or onto the surface of the body. The substance secreted is called a secretion. Glands that secrete internally are endocrine or ductless glands; glands that secrete into a cavity or onto the surface are exocrine or duct glands.

Secretory: an organ that performs the process of secretion

Seizure threshold: the level of stimulation at which a seizure is produced; raising the seizure threshold makes it less likely a seizure will occur

Selenium: non-metallic, chemical element; occurs in several forms; incorporated into proteins that prevent cell damage from free radicals (natural by-products of oxygen metabolism that may contribute to development of diseases); helps regulate thyroid function and plays a role in immune system function

Self-antigens: normal body cells ... Foreign antigens: antigens unlike the self; autoimmune disease occurs when body becomes intolerant of its own cells

Semi-altricial: young birds hatched with eyes open, down feathered, but do not have the ability to leave the nest

Semi-colonial: birds of the same species who nest fairly close to one another and get along

Semi-parasitic: birds which lay eggs in other birds’ nests, but also lay eggs in its own nest

Semi-precocial: young birds hatched with eyes open, down-covered, have the ability to leave the nest but choose not to

Sentinel birds: birds that are susceptible to a particular disease and may be placed in a potentially contaminated area to detect disease; usual mortality in sentinel bird populations should cause suspicion of disease contagion to all birds in inventory; also the bird in the flock that keeps watch

Sepsis/septic: presence of toxins in the blood or other tissues; toxins are produced by bacteria or other microorganisms

Septicemia: invasion and persistence of pathogenic bacteria in the bloodstream; blood poisoning; result of infection; bacteria multiplies and overwhelms the body, resulting in death; affects many organ systems; signs: fever, pinpoint bruising on mucous membranes, lesions in the joints, heart valves, eyes, other organs; treatment is antibiotics

Septum/septal: dividing membrane; no nasal septum in birds

Sequela/sequelae: conditions resulting from and following a disease

Sequester: to separate or detach a small portion from the whole

Sequestrum (bone): fragment of dead bone that becomes detached from the sound portion; necrotic fragment; a piece of dead bone that has become separated during the process of necrosis from a normal/sound bone

Series of events in a disease incident:

  • Peracute: extremely or violently ill, very acute. 
  • Acute: very ill. Very sudden onset and rapid change, short course, acute exacerbation of a chronic condition
  • Subacute: recent onset, somewhat rapid change, poorly defined state between acute and chronic
  • Chronic: on-going, indefinite, virtually no change, long-term condition
  • Intermittent: occasionally

Seroconvert: to produce specific antibodies in response to the presence of an antigen, such as a bacterium or virus; bird can contract the virus, remain asymptomatic, pass it on; bird becomes immune but able to shed the organism to other birds

Serology: science that treats serums and their reactions and properties, esp concerned with antibodies and antigens

Serosa/serosae/serosal: same as serous membrane; outermost delicate layer of serous connective tissue and mesothelial cells that enclose an organ or line a body cavity

Serosanguinous fluid containing or relating to both blood and the liquid part of blood (serum). It usually refers to fluids collected from or leaving the body. For example, fluid exiting a wound that is serosanguineous is yellowish with small amounts of blood.

Serositis: inflammation of the serous membrane

Serotonin; a neurotransmitter, which is a chemical that serves as a messenger between nerves

Serotype: a subdivision of a species of microorganism; e.g., a bacteria, based upon its particular antigens

Serous membrane: thin, moist, transparent membrane that lines the body cavities and surrounds the internal organs; e.g., the peritoneum that lines the abdomen; any thin membrane that consists of a single layer of thin, flat, mesothelial cells resting on connective tissue or a connective tissue stroma, secretes a serous fluid, and lines body cavities or encloses organs contained in such cavities

Serum: plasma from which the red and white blood cells have been removed; watery portion of the blood that results when the blood has been allowed to clot; the clot is then removed; the clot contains the cells

Serrate: with teeth-like saw (cutting edge of the beak)

Sexual dimorphism: male and female of same species have different markings

SGOT/SAST: used as a liver test; tests the enzyme found in multiple tissues, such as liver, heart, muscle

Shallow Acinar: smallest secreting portion of a holocrine sebacious gland; on fold of skin on floor of ear canal; ear wax traps particles and keeps ear canal clear

Shedding of organisms: release of pathogens into the environment from an infected animal; may be in stool, urine, respiratory secretions, vomitus

Shigella: nasty gram-negative bacteria; causes diarrhea, can kill

Shock: result of trauma; inadequate tissue perfusion; signs: apathy, anorexia, loss of voice, dyspnea, sitting on floor, closed eyes, ruffled feathers to conserve body heat, pale mucous membranes; treatment: avoid stress, place in warm, quiet place, administer fluids, Ringer’s Solution If necessary, oxygen therapy, NSAIDS

Shoulder feathers: short feathers overlying the median secondary coverts on top of the wing; near the back; can be seen as the first row of feathers on the wing; also called marginal covers and lesser secondary coverts.  Please refer to Wing Anatomy

Signalment: detailed description; distinctive features for diagnosis of disease

Single-brooded: birds that nest only once per nesting season

Sinuses: open-air spaces found in head (see concha); one sinus is behind the eye, which is why some birds with respiratory illness and sinus infection develop swelling and discharge from the eye

Sinusitis: inflammation of sinuses

Skein: V-flying formation seen in ducks and geese


Skin cytology: examination with microscope of skin scraping or swab; material may be stained and checked for yeast, bacteria, tumors

Skin scraping: taking a scraping off the surface of the skin for microscopic exam; e.g., to check for mites, bacteria

Skylarking: flight pattern put on by male birds; the bird flies high into the sky and flutters to the ground while singing and calling

Small intestine: where most of the absorption of nutrients takes place; liver and pancreas are connected to this tube through ducts

Smooth muscle: found in internal organs such as stomach and intestines, not in heart

Snood: skin hanging from above a male turkey’s beak

Soluble carbohydrates and fiber: easily digested and absorbed Insoluble: passes through

Somatosensory receptors: relating to sensory stimuli from skin and internal organs; perception of the stimuli; receptors receive the stimuli

Spatulate: spoon-shaped bill

Species: level of classification below “genus.” Individuals share distinctive characteristics and are not likely to breed with other species

Specificity: being peculiar to a particular individual or group; host specificity of a pathogen, e.g., parasite

Spectacles: combination of eye ring and suproloral line; large eye ring connected to the lores, displaying a look of eye-wear

Spermatocyte: type of gametocyte that produces sperm

Spirochete: type of bacteria; long, slender, spiral-shaped

Spishing: creating sounds with the lips to attract birds into view

Splanchnic: pertains to viscera; group of sympathetic nerves serving the blood vessels and viscera of the abdomen

Spleen: part of immune system; abdominal organ containing many lymphocytes; large, tongue-shaped organ; filters blood, removes damaged cells; manufactures new blood cells if bone marrow is damaged

Spore: reproductive cell or seed of algae, fungi, or protozoa

Sputum: mucous secretion from lungs, trachea, and bronchi

Squamous: covered with or resembling scales; plate-like 

Squamous cell carcinoma: arises from squamous epithelium, relatively common; occurs on conjunctiva, mouth, salivary ducts, some organs and skin

Squeaking: sound made by birds to attract birds or have them come into view

SSRI: selective serotonin reuptake inhibitors: meds which slow down the ability of nerve cells to absorb serotonin; e.g., Prozac

Staphylococcus: bacteria associated with skin infections

Stain: pigment or dye used to color tissue for aiding identification under microscope

Stasis: in the GI tract, a condition in which the food does not move through normally but remains in one section

Status epilepticus: animal exhibits one severe seizure (Grand mal) right after another, with no time to recover in between

Stenosis: narrowing or restricting of a passage, such as a blood vessel or intestine

Steroidogenesis: production of steroids by adrenal glands

Sternum/Sternal: breastbone, keel; wing muscles attached to it

Stomatitis: inflammation of the mouth or other small apertures; stoma can be artificial opening between hollow organ and outside of body; e.g., to pass wastes

Stratified: to form or arrange in layers

Stress marks/fret marks: caused by periods of stress during feather formation; any stress will cause it; changes in temp, new house, emotional stress, etc. Stress releases endogenous corticosteroids

Stricture: abnormal narrowing of a passage in an organ such as a blood vessel or intestine

Stridor: roaring sound during respiration, harsh respiratory  sound heard during inspiration in laryngeal obstruction

Stripes: feather color that runs the length of a bird’s body

Stroma: connective tissue or framework of an organ, gland, or other structure, as distinguished from parenchyma

Strongyle: nematode parasite, worm

Stupor: state of mental dullness; failure to normally respond to stimulus

Subcapsular: beneath/below a membranous sac or integument

Subchondral bone: the bone below the cartilage; provides support for the cartilage on the articular surface

Subclinical: disease below clinical level: bird is ill but not showing signs; early stage or mild form of disease

Subcutaneous: beneath the layers of skin

Subcutanous emphasema: Trauma or puncture of an air sac will cause air to be trapped under the skin, creating large balloons;. The chick in the picture had its air sac punctured by the parents, but surgery corrected the problem and the chick survived.

Subluxation: partial dislocation of a joint in which the bones become out of alignment but the joint itself is still intact

Subserous/subserosal: situated or occurring under a serous membrane

Sub-species: or races; identifies different birds belonging to the same species but show no noticeable difference among themselves

Subterminal spots: (mirrors) spots seen on the outer tip of the primary feathers, mostly in gulls

Sulci/sulcus: a groove or fissure between two convolutions of the brain

Sulfonamides: class of antibiotics which contain sulfur; they are bacteriostatic, stopping the growth of bacteria without killing them

Superciliary line: arch of feathers growing overtop the bony arch of each eye; same location as human eyebrow; aka supercilium or eyebrow; outline the face of the bird

Superspecies: races of birds in which each has its own geographical location

Superior umbilicus: area on shaft of a feather closest to the barbs and afterfeather

Suppurative/supperate: to produce or discharge pus, as a wound; the pus itself

Supraloral line: the line above the lore; in many species it is the brightly colored line between the eye and beak

Supraventricular tachycardia: heart beats very rapidly because of signals coming from the atrium or near the junction of the atria with the ventricles

Sustentacular tissue cells or fibers whose only function is to serve as a support for other tissue

Swoop: descent of bird on prey

Sympathetic nervous system: (SNS) one of the 3 major parts of the autonomic nervous system (others are enteric and parasympathetic systems); its action is to mobilize the body’s nervous system fight-or-flight response; constantly active at a basic level to maintain homeostasis

Sympathomimetic: producing effects similar to the flight-or-fight response; effects include increased heart rate, sweating, increased blood pressure

Sympatry: different species together in same area

Syncope: temporary loss of consciousness, fainting

Syndactyl: two front toes partially joined, as in kingfishers

Synechia: adhesion of iris to cornea or lens

Synergist: agent that enhances the action of another

Syngamiasis: roundworm infestation

Synostosis: normal or abnormal union of 2 or more separate bones to form a single bone; fixed bones through attachment; e.g., tarsometatarsus

Synovia/synovial membrane: certain membranes, esp joints, secrete a lubricating fluid resembling egg whites

Synovial: pertaining to a joint made of bone ends and ligaments covered with cartilage; a cavity filled with synovial fluid and an outside fibrous capsule; e.g., hip or elbow joint

Synovial fluid: bursae and synovial joints have inner lining called synovial membrane; it secretes a fluid which acts as a lubricant to make joint movement smooth

Synovitis: inflammation of a synovial membrane

Synphysis: a fibrocartilaginous fusion between two bones; a type of cartilaginous joint; a slightly movable joint; a growing together of part or structures; symphyses are permanent

Synsacrum: last 2 vertebrae of lower back (pelvis) and first 2 tail vertebrae joined as a unit for purpose of flight

Syrinx: organ at the base of the trachea; there, it branches and bifurcates to form the primary bronchi; used for sound production

Syringeal membrane: real sound producers are the muscles that surround the syringeal membranes. As air passes over these membranes they begin to vibrate, and while they are vibrating, the surrounding muscles apply controlled tension which results in sounds of varying pitches

Systemic: refers to total body involvement

Tachycardia: rapid heart beat

Tachypnea: excessively rapid respiration rates

Tail: long feathers extending from pygostyle; used for balance and attracting mates

Tail coverts: short feathers covering the bases of the long tail feathers

Tail numbering: system of assigning a number to each tail feather; conveys certain characteristics about a species

Talons: elongated claws on birds of prey

Tarsal: the lower leg that contains the tarsometatarsus or ankle/foot bones

Tarsometatarsus: the bone underlying the tarsus; consists of fused bones; between ankle and foot

Tarsorraphy: suturing of a portion of or entire upper and lower eyelids in order to shorten or close the palpebral fissure

Tarsus/tarsi: lowest segment of leg before the toes; between the knee and the foot

Taste buds: lie at base of tongue, on roof of the oropharynx on either side of the choana, and on floor of the oropharynx in the front end of the laryngeal mound

Taxonomy: classification of organisms in an ordered system that indicates relationships: Kingdom, Phylum, Class, Order, Family, Genus, Species

T-cell, T-lymphocytes: circulating cells responsible for cell-mediated immunity; made in the thymus organ in neck, stored in the spleen, found in the blood;T-cells may directly kill a cell or produce chemicals called lymphokines that activate macrophages which will kill the cell. Compare with “B cell.”

Temperature: 105-107 in birds; birds less capable of maintaining body temp than mammals

Temporal canthus: outer corner of the eye closest to the ear

Tenacious: viscid (having a glutinous consistency), adhesive

Tendon: band of fibrous connective tissue that connects muscle to bone

Tenesmus: difficulty passing droppings due to papillomas

Tenotomy: surgical cutting or division of a tendon

Teratatomas: tumor made up of different types of tissue; usually found in ovary or testes

Territory: region determined by breeding pairs and defended from predators

Tertials/tertiary feathers: flight feathers attached to humerus (basal joint of the wing) next to the secondaries (refer to Wing Anatomy)


  • Parallel: different tests at same time
  • Serial: repeated tests over time

Test sensitivity and specificity: Tests that determine a test’s usefulness

  • Sensitivity is a measure of the test’s ability to accurately detect antibodies in an infected bird; identifies diseases early
  • Specificity is the percent of noninfected birds that test negative

Tetany: condition usually due to low blood calcium (hypocalcemia); characterized by cramps, spasms of the hands, feet, larynx; bird has overactive neurological reflexes

Third intention: manner of healing (delayed primary closure); occurs when a wound is initially too contaminated to close; is then closed surgically 4-5 days after the injury; drains are inserted to provide an outlet for removing accumulations of serosanguinous fluid and purulent material and for obliterating dead space

Thrombocytopenia: low level of platelets

Thymoma: lymphoma of thymus gland in neck

Tibia: leg bone between the knee and ankle

Tissue: a group of specialized cells that is similar in structure and function; Four types:

  • Epithelial: covers internal and external body surfaces
  • Connective: adds support and structure to a body part; holds organs in place and binds parts together
  • Muscle: has specialized ability to contract and relax
  • Nervous: has specialized ability to react to stimuli and conduct electrical impulses

Titer: a measure of the number of antibodies in the blood

Toes: Digits 2,3 point forward, digits 1,4 point back. Numbered from hallux toe (short inside back toe) clockwise on the right foot, counterclockwise on the left.

Tom: male turkey

Tomium/tomia: cutting edge of maxilla and mandible on side of beak; referred to as upper and lower mandibular tomia

Tonometry: measure of tension or pressure; e.g., intraocular pressure

Torticollis: stiff neck caused by spasmodic contractions of the muscles; animal draws head to one side with chin pointing to the other side; aka wryneck; often caused by trauma

Tortuous: full of bends, turns, twists

Totipalmate: all toes joined by webs

Toxemia: a condition in which toxins move into the bloodstream

Toxic: toxicity of cells; refers to being poisoned; detoxification refers to removing toxin

Toxin: the poisonous, causative agent of disease; of plant or animal origin

Toxic heterophils: toxic heterophil is “sick” from fighting disease; serious; an example of abnormal leukocyte morphology

Trabecula (trabeculae): small beam or supporting structure; fibromuscular bands or cords providing support to various organs; in bone they form a meshwork of intercommunicating spaces which are filled with marrow or air in birds, depending on whether long, pneumatic bones or smaller bones

Trachea: windpipe

Tracheitis: infection/inflammation caused by bacterial or viral agent

Tracheal mucosa: consists of smooth, stratified squamous epithelium tissue

Tracheobronchitis: inflammation of the trachea and bronchi

Trailing edge of wing: edge seen when wing is stretched out in flight and viewed from the rear: leading edge is the area in the front part of the extended wing  (refer to Wing Anatomy)

Transient: a bird seen in an area located between its breeding and non-breeding zones

Transfusions: IV infusion best taken from same bird or same species

  • Autologous blood donation: derived from the same individual; previously donated blood; individual receives his own blood
  • Homologous: IV infusion of blood that has been donated by another bird of same species
  • Heterologous: blood received from individual of a different but related species; e.g., from a lovebird to a cockatiel; least desirable method

Transport host: animal or insect which carries an immature parasite from one host to another

Transillumination: to throw a light across or through an organ as a means of diagnosis

Transudate/transudation: to pass through a membrane

Trepanation: creating a temporary opening in sinuses so that antibiotic solutions can be instilled over a period of time

Trephine: surgical instrument (crown saw) used to cut out circular sections

Tremors: uncontrolled shaking

Trichoepithelioma: uncommon condition; single lesion or multiple benign tumors arise on the face after puberty; rounded skin nodule that may ulcerate

Trichomoniasis: disease of GI tract caused by trichomonas, a flagellated protozoan

Tricyclic antidepressant: works by decreasing the amount of certain chemical transmitters taken up by specific nerve cells; used to treat behavioral problems in small animals; they act by inhibiting reuptake of norepinephrine and serotonin by blocking the transporters responsible for reuptake of these neurotransmitters.

Tri-chrome: test for giardia and other protozoa; suspends the parasites, making them easy to find

Trocar: sharp, pointed instrument enclosed in a cannula; used for withdrawing fluid from a cavity, as the abdominal cavity

Trochanter: either of two knobs at the top of femur; greater on the outside and lesser on the inside; serves as attachment of muscles between the thigh and pelvis

Trochlear: the bony or fibrous structure through which or over which tendons pass, or with which other structures articulate; e.g., femoral: the articular surface on the cranial aspect of the distal femur upon which the patella glides

Tropism/tropic: involuntary response of an organism or one of its parts toward or away from a stimulus, such as heat or light; movement in response to a stimulus; having and affinity for a specific body part, e.g., neurotropic virus

Truncus/trunci: main body part to which head and limbs are attached; trunk; a large structure such as a vessel or nerve, from which smaller divisions arise

Trunk: whole body section between neck and tail; contains:

Thorax: bounded by rib cage, sternum (keel) and vertebral column (backbones)

  • Abdomen and pelvis: not separated by well-defined boundaries

Tubercle: a round nodule, small eminence, or warty outgrowth found on bones or skin, or in TB, in lungs

Tuberosities: an elevation or protuberance, esp one on the bone where a muscle is attached

Tubule: microscopic ducts; tubules in the kidneys concentrate the urine

Tumors: abnormal tissue growth resulting in a mass that may be benign or malignant

  • Wing tumors: swellings or masses anywhere on wing; large masses with muscles or skin on wings;
  • Bone tumors: surgery for amputation immediately

Tunica media: middle coat of blood vessels

Turbid: cloudy, as in urine

Turgid/Turgidity: swollen, distended

Turgor/turgescence: normal rigid state of cells caused by outward pressure of water content of each cell on its membrane

Tympani: vocal organ valve that produces the birds’ sound

Typhitis (cecitis): inflammation of cecum or large intestine

Ubiquitous: found everywhere, around the world

Ulcer: lesion in which the tissue surface is eroded away

Ulceration: open sores

Ulnar vein: vein by the ulna bone in forearm, opposite the alula, used for blood draw

Ultrasound: used in larger birds to characterize lesions, wounds, injury, disease

Underparts: visible when viewing from below when bird is in flight: belly, undertail coverts, chest, flanks, foreneck, underwings

Undertail coverts: feathers in a triangular area on the undersurface of a bird between vent and base of tail feathers (crissum)

Underwing: bottom side of wing  (refer to Wing Anatomy)

Underwing coverts: small feathers that cover the base of the bird’s underwing (refer to Wing Anatomy)

Upperparts: visible when viewing from top: back, rump, hindneck, wings and crown 

Uppertail coverts: small feathers that cover the base of the upper side of the tail feathers and rump

Upperwing: seen from top view  (refer to Wing Anatomy)

Undifferentiated: in neoplasia refers to a primitive cell type and having no special structure or function as yet; immature cell, likely to be malignant

  • Differentiated: marked or formed differently from other cells; distinct; changed from a generalized form into a form specialized for a tissue, organ or other body part

Undifferentiated precursor: can’t tell difference between things that came before.

Unthrifty: dull, listless, underweight, poor health

Upper tail coverts: single row of feathers covering the bases of the tail feathers (rectrices)

Urates: white portion of the droppings, crystalline urine; chemical compound which contains uric acid; made by the kidney and can form crystals and stones in the urodeum (urinary bladder);

Uric acid is concentrated uric acid, a waste product from the breakdown of certain proteins;

  • Abnormal colors: yellow or green =liver disease; brown, rust-red= heavy metal toxicity

Urate fraction: urate part of the droppings

Urea: waste product of protein metabolism that is removed from body by the kidneys

Urease: (yur-ee-ase) An enzyme that breaks down urea;

Uremia: waste products in the blood, as in kidney disease

Ureter: tube that carries urine from kidney to urinary bladder to cloaca Uric acid: end product of protein metabolism; main nitrogenous waste; elevations occur with significant kidney disease

Uricemia: increased uric acid in the blood; leads to gout

Uricosuric: excreting of uric acid in urine

Urinary system: removes wastes by filtering blood; urea is major waste product of protein metabolism; it is filtered by the kidney and used to determine health status of kidney; system maintains proper balance of water, electrolytes and acids in body fluids and removes excess fluids from body; maintaining proper balance of these allows body to achieve homeostasis

Urinary tract infection (UTI): invasion of microorganisms in the urinary tract; results in local cellular injury

Urodeum: part of cloaca that holds urine, urates, sperm and egg; middle and smallest chamber in cloaca; separated from other two by mucosal folds; ureter and left oviduct open into urodeum

Urolith/urolithiasis/cystolith: stony masses in urinary tract

Uropoisis: process of urine production

Uropygial gland: sebaceous gland; papilla on top of uropygium that secretes oils for preening; the oil:

  • keeps skin supple and feathers and scales from becoming brittle;
  • has waterproofing effect in some species;
  • has antibacterial and anti-mycotic properties
  • has an odorant and pheromonal function; sense of smell is better developed in birds than formerly realized;
  • plays a role in reducing skin infections, sex identification;
  • secretions reflect ultra violet light which birds can see;
  • helps body absorb Vit. D Uropygium: fleshy posterior end supporting the tail

Uveitis: inflammation of the iris

Vaccine/vaccination: given to establish resistance or immunity to an infectious disease; a suspension of infectious agents, either killed or weakened

Vacuoles: spaces or cavities in cell cytoplasm

Vagrant : a bird seen outside its breeding zones or natural habitat

Vagus nerve: Cranial nerve X, controls the GI system and heart

Valgus: joint, bones or feathers turned outward to an abnormal degree. Aka angel wing; mostly in fledgeling waterfowl, but also in psittacines; caused by valgus deformity in carpometacarpal bones which rotate laterally 180 degrees; causes hatching problems, caused by lack of protein, genetic, calcium imbalance; results in too–rapid growth of blood-filled, heavy primaries being carried on inadequately mineralized bone; therefore it’s a metabolic bone imbalance; young birds can be corrected with splinting; older birds require osteotomy then pinning

Valve: membranous fold which controls blood flow

Valve stenosis: narrowing or constriction of a valve

Vanes: rows of interlocking barbs that protrude from shaft on feather

Varus: position of a leg joint turned inward to abnormal degree;

Vascular Intima: innermost coat of a blood vessel

Vascularity: vessels or ducts that convey fluids, e.g., blood or lymph

Vasculitis: inflammation of blood or lymph vessels

Vascular/vascularized: pertaining to, composed of, provided with vessels or ducts that convey fluids, as blood or lymph; rendered vascular by the formation of new blood vessels or supplied with blood vessels

Vasoconstriction: a decrease in the diameter of blood vessels

Vasodilator: agent which dilates, or increases the diameter of blood vessels

Vectors: animal or organism that carries disease from one host to another; e.g., mosquito

Veins: return blood to heart, have thinner walls and are less elastic than arteries; have valves that permit blood flow toward the heart and prevent blood flow away from the heart

Vena cava: either of two large veins carrying blood to the right atrium of the heart. The cranial vena cava brings blood from the head region, front legs, and upper chest to the heart; the caudal (posterior) vena cava carries blood from the areas of the abdomen and hind legs to the heart

Vent: opening of cloaca to the outside; located between the belly and base of the underside of the tail feathers

Vent glands; small, tubular glands on the lips of the vent; outside or inside, they secrete only mucoproteins; they enlarge during breeding season

Ventricles: chambers of the heart that pump blood

Ventricular arrhythmia: heart beats irregularly and/or at an abnormal rate because of signals coming from the ventricles

Ventriculus: second part of stomach; grinds the food for absorption in the small intestine; produces pepsin and other enzymes

Vermiculation: description of fine, waving lines seen in a bird’s plumage; also wavelike contractions of intestine (peristalsis)

Vertebra/vertebrae: small bones in spine: 12 neck, 8 thoracic, 8 lumbar, 8 tail (fused at pygostyle)

Vertebral: referring to the individual vertebrae of the spinal column or to the entire spinal column

Vesicle: small, elevated area on the skin filled with a clear fluid

Vestibular system: portions of the inner ear, nerves and brain which help the body maintain balance

Vestigial: A small, imperfectly developed part or organ which has been more fully developed in past

Vestigial toe: small, spur-like toe, seen above the feet and back of the leg of waterfowl

Vestigial ovary: the right ovary and oviduct of birds. Only the left ovary and reproductive organs are full-sized and functional

Vinaceous: a purplish-pink color in the plumage of some birds

Vinculum: end of the ulna bone as part of the elbow joint

Viral drift: mutations or genotypes

Viremic: virus in the blood

Virulence: competence of any infectious agent to produce disease;the degree of bodily damage it is capable of producing; strength of the pathogen

Virus: simple, non-cellular parasite that can reproduce only inside living cells; smallest form of life; infectious unit that enters and uses cells for replication; cause disease

Vicera/visceral: pertaining to any interior organ in any of the great body cavities, esp in abdomen

Viscerocutaneous: pertaining to the internal organs and skin

Viscosity: thickness of a fluid

Viteline membrane: transparent membrane surrounding and holding together the yolk of an egg

Vitello: yolk

Vitellogenesis: yolk formation

Vivipary/viviparous: live births

Volvulus: torsion or twisting of the intestine, causing obstruction

Vomer: a bone forming part of the nasal system

Wattle: fleshy skin that hangs from the lower bill of turkeys and chickens

White blood cells: major role is defense against invading organisms; e.g., bacteria, viruses, fungi; different types of leukocytes:

  • Lymphocytes: part of immune system, kill foreign invaders
  • Monocytes: associated with chronic disease
  • Eosinophils: defense against parasites, inflammation
  • Neutrophils/basophiles: contain histamines and are involved in inflammatory reactions

White blood count: total number of white cells per low-power field; measure of normal vs. disease state

Whole seed in feces: causes: PDD, candidiasis, increased motility, nematode parasites in GI tract, megabacteria

Wing bars: striping on bird’s wing covering the base of the flight feathers (refer to Wing Anatomy)

Wing projection: the projection of the primaries beyond the tail feathers, seen from the side of a standing bird  (refer to Wing Anatomy)

Wing tips: the tips of the primaries, seen from the side (refer to Wing Anatomy)

Wish bone: see “furcula”

Wrist: carpometacarpus, where manus joint begins

Wry neck (torticollis): Abnormal twisting of head due to injury, disease, or nutritional imabalance

Xanthoma: benign tumor composed of lipids and cholesterol; associated with hypothyroidism, clostridium, subclinical/clinical illenss, high-fat seed diet, poor immune system

Xeropthalmia: abnormal dryness and thickening of the surface of the conjunctiva and cornea of the eye; caused by Vit A deficiency or local disease

Xerophilic: adapted to dry environments

Yersiniosis: (pseudotuberculosis): septicemia with gastroenteritis; signs: fever, toxemia, high fatality rate; high number of embolic absesses on most organs at necropsy

Yolk: yellow portion of egg containing all the lipids and most of the protein needed by developing embryo; surrounded and held together by vitelline membrane

Yolk stroke: convulsions, paralysis, not moving on floor of cage, torticolis; caused by yolk laid internally

Yolk peritonitis: lethargy, tail bobbing, abdominal swelling, recently laid eggs or laying imminent; yolk misses oviduct, spills into abdominal cavity; lethal, sudden death; surgery needed to flush out abdominal cavity; removal of oviduct required

Yeast: unicellular fungi that reproduce by budding

Zoonotic/zoonosis: disease which can be transmitted between animals and humans

Zygodactyl FootZygodactyl/zygodactylous: psittacine foot arrangement; 2 toes forward, 2 toes back

Zygomatic arch: bony arch at the outer border of the eye socket; formed by union of cheek bone and temporal bone

Zygote: fertilized egg or the developing individual produced from such a cell

Xerophilic/xerophile: birds which prefer dry habitats

Some references from:

Photo of author

Jeannine Miesle

Jeannine Miesle, M.A., M.Ed, Allied Member, Association of Avian Veterinarians is an important contributor to Beauty of Birds. Jeannine has done considerable writing, proofreading and editing for journals and newsletters over the years. She had taught English and music in the schools and presently is an organist at Bethany Church in West Chester, Ohio. She also administrates a Facebook group, The Science of Avian Health.

Jeannine takes in rescued cockatiels and presently has twelve birds. When they come to her they remain as part of her flock.