Psittacine Beak and Feather Disease
Psittacine Beak and Feather Disease (PBFD) was first described in various cockatoo species in Australia in the 1970’s. Since then, it has been recognized in birds all over the world. Typically thought of as a disease of parrots, it has also been diagnosed in song birds, pigeons, doves and domestic geese. The birds most commonly and severely affected tend to be “old world” parrots such as lovebirds, cockatoos, cockatiels, eclectus, budgerigars and African Grey parrots. AS the name implies, affected birds typically have abnormal feathering and may have changes of their beak or nails. The disease is caused by a type of virus known as a circovirus. The virus is shed in the feces, crop secretions and feather dust of affected birds and can remain in the environment for months.
Birds become infected, usually at an early age, through contact with contaminated surfaces. Most birds will begin showing signs by 3 1/2 years of age. Acute infection usually results in depression followed by bending, breaking and premature shedding of developing feathers. Chronically infected birds will develop increasing numbers of abnormal feathers with each successive molt. This has led PBFD to be referred to as “French Molt” by many aviculturists. Deformities of the beak and toenails may also develop. The beak often becomes overgrown and misshapen with areas of dead or necrotic tissue. The outer layers may crack and flake off allowing secondary infections with bacteria or fungi to set in. Similar changes are seen in the toe nails which may actually slough off in severely affected birds. As the disease progresses, the virus attacks the bird’s immune system. With a weakened immune system, affected birds ultimately succumb to secondary infections with bacteria, fungi or other viruses. Once clinical signs appear the disease usually continues to progress, though some South American species of parrots have been known to recover.
Simple blood tests exist which can test for active infection with or exposure to the virus which causes Psittacine Beak and Feather Disease. Affected birds should be removed from aviaries and isolated to decrease the chance of spreading the virus to other birds. All positive birds should be re-tested in two months time to determine if they have been able to rid their bodies of the virus. If they are still positive after two months it is likely that they will remain persistently infected for life. While there is no cure for PBFD, affected birds can benefit from supportive care while treating the secondary infections with appropriate antibiotics or antifungal medications.
