Psittacine beak and feather disease
Dr T van Egdom BVSc
PBFD is a viral disease affecting only the parrot family. It was described for the first time in the 1970’s in several species of Australian Cockatoo. Today Old World parrots (birds from Africa) seem to be a lot more susceptible to the disease than New World parrots. The disease is transmitted mainly by feather dust of affected birds, but the virus has also been isolated from faeces and in small quantities in the crops of sick birds. It is thus theoretically possible that infected birds could transmit the virus to their young during crop feeding, but this seems to happen very infrequently. The virus could also be transmitted to the young through the egg.
Transmission
The most important and most common means of transmission is via the feather dust of sick birds. PBFD is a highly contagious and fatal disease. (A small number of birds may rid themselves of the virus through their immune systems though.) PBFD is similar to AIDS in humans in some respects.
Chronic form
PBFD is a chronic debilitating disease that is characterised in the later stages by abnormal underdeveloped feathers and a necrotic, abnormal beak. Affected birds are very susceptible to secondary infections because of the virus's immune suppressive effects and it is usually these secondary infections causing death. Unfortunately no treatment exists, but good nutrition and early treatment of secondary infection may help such a bird to live for extended periods of time. Because of the contagious nature of the disease it is however problematic to keep such an animal in a multibird household. Please ask your vet for more information.
Acute form
The acute form of the disease usually occurs in young birds between 8 and 13 weeks, but may be seen in birds as old as 8 months. These birds become very sick, with puffed up feathers, a weak or absent eating reflex and sometimes showing vomition. They are usually very weak. The virus affects fast growing cells such as those of the liver, bone marrow and red blood cells. They often suffer from anaemia and this is more often than not the cause of death. 99% of affected baby birds die within 1-6 days after having fallen ill due to the anaemia.
Treatment
Treatment is based on treating secondary infections and combating dehydration but it is usually ineffective.
Prevention
Biosecurity: All birds bought in should be tested within a week for PBFD. If positive the bird could be returned to the supplier. You could also retest the bird after a month since a small number rid themselves of the virus. In the case of breeding birds a second positive test definitely warrants culling since the virus could be transmitted to the offspring via the egg. It is of great importance to quarantine all new birds for a month to prevent spread of disease to the healthy flock. Even though sick baby birds may die before test results are available this should be done in the light of the risk to other birds in the household and possible implications when aquiring a replacement.
Please consult your vet in this regard to save yourself lots of trouble. The most important preventive measure is to buy birds from reputable breeders whose birds have tested negative for PBFD.