Feather cysts

A feather cyst forms when a growing feather cannot break through the skin, so it curls up and keeps growing inside the follicle. The result is a lump filled with feather material and a yellowish, cheesy mass. It is most often seen in canaries, but it can also occur in parrots and other birds.

Every feather grows from its own follicle in the skin. If growth is disrupted, the feather cannot emerge properly, curls up and stays trapped under the skin. The follicle fills with feather debris and keratin and gradually gets bigger.

The main causes:

• Hereditary predisposition – the main cause in canaries. It is probably linked to breeding for a particular type of plumage. Breeds such as the Gloster and the Norwich are often mentioned, and the problem is more common in birds with soft, “full” plumage. For this reason, birds with cysts should not be used for breeding.
• Follicle injuries – skin injuries, a feather that was previously plucked or broken, pecking by other birds.
• Skin and follicle infections – can damage the follicle so that the new feather grows abnormally.
• Poor general condition – a poor diet and weak plumage can contribute to the problem.

Feather cysts are not contagious and do not spread to other birds.

In parrots and other birds, feather cysts are less common and usually single, most often on the wings at the site of an old injury. In canaries prone to cysts, they often appear in several places and come back after every moult.

• a round or elongated lump under the skin, most often on the back, wings or chest
• a curled feather or a yellowish, cheesy mass may be visible inside the lump
• a feather is missing at that spot, or the feathers look untidy
• the lump grows over time, and new ones may appear elsewhere
• redness, swelling or a scab if the cyst becomes inflamed or bursts
• the bird pecks and scratches at the spot

Small cysts usually do not bother the bird. With large, numerous or inflamed cysts, the bird may become lethargic, lose its appetite and lose weight, and the cyst may bleed. In severe cases feather loss also increases.

A lump on the skin can also be caused by something else, such as a fatty tumour, an abscess or another growth, so it should be shown to a vet.

• the cyst is bleeding or has burst
• it is red, hot, swollen or oozing pus
• it grows quickly, or several new lumps appear
• a cyst on the wing interferes with flight, or the bird cannot fold the wing because of it
• the bird is fluffed up, sleepy or not eating

A vet usually recognises a feather cyst by its appearance and location. If unsure, they may take a sample of the contents or the growth and send it for testing to rule out a tumour or abscess.

In birds with many cysts, the vet will also look at the general condition, diet and quality of the other feathers, because poorer condition can make recovery after surgery harder.

The only permanent solution is surgical removal of the entire follicle, carried out by a vet under anaesthetic. If only the contents are emptied, the follicle remains and the cyst almost always comes back.

• Follicles have a rich blood supply, and canaries are tiny, so losing even a small amount of blood is dangerous for them. That is why only a vet should perform the procedure.
• For inflamed cysts, the vet may prescribe an antibiotic.
• In birds with many cysts, the vet assesses which ones need to be removed and which can simply be monitored.

Never lance, squeeze or cut a cyst yourself. There is a risk of heavy bleeding and infection.

• Check the bird regularly and keep an eye on the size of the lump.
• Make sure other birds do not peck at it. If necessary, separate it temporarily.
• After surgery, keep it in a clean, warm, draught-free cage in a quiet place and follow the vet's instructions.
• Offer a varied diet so the plumage can regrow in the best possible condition.

If a cyst gets injured by accident and bleeds, press gently on the spot with clean gauze and contact a vet immediately. In tiny birds even brief bleeding can be dangerous.

• Do not breed birds that have feather cysts or come from lines prone to cysts.
• When breeding canaries, choose healthy birds with good plumage.
• A balanced diet, especially during the moult.
• Enough space and a calm environment to avoid injuries and feather plucking.

Feather cysts are not contagious and are often hereditary, especially in canaries. Small cysts should be monitored, while large or inflamed ones should be left to a vet. Never open them yourself at home.