Psittacine Beak and Feather Disease

General Information
This disease was first described in Australian cockatoos in the early 1970's. Since that time, the disease has infected over 50 different species of birds. The virus causing the disease works slowly; the disease is often called "Bird AIDS" due to some similarities between it and the AIDS condition seen in people.

What causes beak and feather disease?
For many years, the cause was unknown. We now know that a virus causes the disease.

How do birds become infected with the virus?
Susceptible birds can become infected through the oral cavity, nasal passages, and through the cloaca (the common receptical in which the urinary, gastrointestinal and genital tracts empty). The virus is readily shed in the feces and in the crop. Viral particles in the crop (storage part of the stomach) may explain how the virus is passed from parents to offspring. High concentrations of the virus are shed in feather dust from infected birds.

What are the signs of beak and feather disease?
As is the case with the HIV virus in people, infected birds may take months to years before showing any clinical signs. Once signs are seen, most birds die from secondary infections within 6-12 months.

Clinical signs involve lesions affecting the beak, feathers, or both. Most commonly, young birds (less than 3 years old) are infected with the virus. Several forms of the disease may be seen; the forms of the disease are influenced by the age of the bird when infected.

Peracute Form: This occurs in neonatal (recently hatched) birds; signs seen are septicemia (bacteria and bacterial toxins in the blood stream) accompanied by pneumonia, enteritis (infection of the small intestine), weight loss, and death. The diagnosis is easily missed if a necropsy (post mortem / autopsy) is not performed on birds that die suddenly.

Acute Form: The acute form develops in birds infected in young birds as they develop their first feathers. Depression followed by grossly formed developing feathers and often death is seen.

Chronic Form: This form occurs in older birds and is seen as abnormal feathers during molts. Short, clubbed feathers and deformed curled feathers are seen. If birds live long enough they may develop baldness.

Beak deformities may develop, and if they do, these occur after a long course of the disease where substantial feather changes have taken place.

How is the disease diagnosed?
A skin and feather biopsy can be used to eliminate other causes of abnormal skin and feathers. It is not 100% diagnostic for beak and feather disease but can be strongly suggestive of it. A blood test using a DNA probe is the best way to diagnose the disease; it is often performed at the time of the biopsy.

How do I know if my bird is infected?
Birds can be screened for the virus using a simple blood test. New birds should be screened for the disease; if the bird is infected, it probably won't show clinical signs for quite a while and the owner needs to be informed of this. Additionally, many new birds are sold with a health warranty. A bird testing positive should be covered under the warranty and the owner may decide to return it. Any owner purchasing a new bird would have the resident bird and new bird tested before bringing the new bird into the household.

How is beak and feather disease treated?
Unfortunately, there is no treatment for the disease and it is usually fatal. Supportive care can be given and can extend the life of the bird for quite some time. Infected birds should be kept separate from non infected birds as the disease is easily transmitted.