A Bird’s Oil Gland – also known as Uropygial Gland or Preen Gland – Location and Function:
During preening, birds gather oily secretions that contain diester waxes from their oil glands. This gland is located near the base of (just above) the tail.
Birds distribute the oil over the plumage. The function of this oil is somewhat disputed. All will agree that it serves to maintain and condition their skin and feathers. In all likelihood, it helps to waterproof the plumage (a concept that is not universally accepted, but appears likely – particularly in water birds).
However, some authorities state the water-proofing effect is primarily achieved by dense feathers that insulate by trapping air thus maintaining an air-tight surface and – in some birds – a water-tight structure.
Some bird species- those that are less likely to bathe or immerse themselves in water – produce feather dust instead of oil glands. They have powder down feathers that shed a very fine, white, waxy powder composed of keratin that is spread through the feathers when the bird preens itself.
This “dust” fulfills the same function of the oil glands, as it forms a waterproof barrier for contour feathers. Those species that produce the greatest amount of feather powder are Cockatiels, Cockatoos and African Greys.
The secretion from this gland also has antibacterial and anti-mycotic properties; as well as a potential odorant and/or pheromonal function (aids in the attraction of possible mates).
The oil glands of some bird species (i.e., Hoopoes) produce a foul-smelling liquid (specifically when breeding) that birds rub into their plumage. The bad smell is believed to keep predators away from nesting females and their young, as well as deterring parasites. The bad odor of the secretions ceases just before the young fledge.
Inactive, Impacted, Blocked or Ruptured Oil Gland
A well-functioning oil gland will help a bird keep the feathers in good condition, in addition to water proofing and insulating the plumage.
Poor feather quality:
The gland occasionally gets blocked or stops producing some or all of its oil, at which point the feather quality typically deteriorates.
An impacted oil gland is usually clearly visible by the time you notice a difference in feather quality.
An atrophied oil gland can cause seizures. As the oil gland produces vitamin D3 precursors that are spread into the feathers as the birds preen themselves. Upon exposure to ultraviolet light, the precursors will be converted to active D3, which will then be ingested when the birds preen themselves again.
Testing an oil gland …
- Check for Swelling: The first course of action would be to part the feathers over the oil gland and check on the condition of the oil gland. If there is an unusual swelling, this would indicate an impacted oil gland.
- Verify Oil Production: Gently roll the gland (“wick”) through your fingers, and then check your fingers for greasy spots. If your fingers look and feel very oily, the oil gland is working. If no secretion are seen or felt, gently massage the gland and then check again. If you can only feel a little oil, the oil gland may not be functioning properly or may be completely blocked.
- Tumor: The preen / oil gland is enlarged and distorted in shape. As a result the small feathers over the gland become raised and the tail feathers tend to fall out and not regrow.
- Infection: An oil gland malfunction can be caused by an infection and a vet may prescribe Baytril or another broad-spectrum antibiotic for 7 – 14 days.
- Stress can also cause a failing oil duct. This often happens, when captive birds are being picked upon by other birds in their environment. In this case it is best to separate them from the aggressive birds.
- Malnutrition can also cause oil gland problems; such as Vitamin A deficiency. A proper diet and potential supplementation should be discussed with the vet. Adding wheat into your bird’s diet may also help the gland to recover and produce more oil. To this end, some vets recommend adding SMALL amounts of fish oil to a bird’s diet. Too much fish oil can get messy. Some people have added cat kibble with fish oil to their bird’s diet instead.
Treatment of Ruptured Oil Glands:
- Ruptured glands must be surgically removed immediately; following the surgery, the plumage will obviously no longer repel water
- Antibiotics need to be administered.
- A drain may need to be inserted for a few days
Other potential treatments:
- Antibiotics may need to be administered.
- An impacted / blocked oil gland might be resolved with the use of hot packs (not too hot to burn the sensitive skin of a bird!). The hot pack should only be “warm”. This “hot pack” held gently against the oil gland may help.
- Gentle massage to the gland two or three times a day
- Reducing stress and improving diet.
- Some vets may suggest lancing the gland (releasing pus or pressure built up).
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