Is this a disease which the average parrot owner should be concerned about? What are the symptoms?
Absolutely! All parrot owners should know about Psittacine Beak and Feather Disease (PBFD).
Psittacine beak and feather disease is caused by a circovirus. This virus causes a wide range of clinical signs associated with progressive feather and beak abnormalities. Birds can be infected by inhaling, swallowing or absorbing viral particles shed in feather dust, crop secretions, and feces of carrier or sick birds.
Old World species (Cockatoos, African Greys, Lovebirds, etc.) are typically birds in which the disease is fatal. New World species (Macaws, Amazons, etc.) can be affected, although the reported incidence of disease is lower and the potential for recovery is more likely. Clinical disease and incubation times depend on many factors, including the species exposed, how old the bird is when exposed, how aggressive the viral strain is, how much of the virus the bird is exposed to, the route of exposure and the health of the bird during exposure.
PBFD can have peracute, acute, and chronic forms. The peracute form is usually in young birds which typically die due to infection. Because of the rapid nature of this form, there are rarely classic feather abnormalities. Without an autopsy, this form of PBFD can be missed.
Acute PBFD is characterized by depression that may last several days, followed by mild to moderate feather abnormalities. Hemorrhages in the feather shafts and premature molting of abnormal feathers are quite common. These birds often have secondary infections and anemia. Molting often makes recognizing PBFD more evident.
Chronic PBFD is the classically recognized form of the disease and is the result of surviving an acute case of PBFD. These birds typically have missing feather tracts, colour changes to the feathers, feathers that remain in their sheaths, and a loss of powder down feathers, resulting in abnormally shiny beaks. Feather abnormalities may progress at each successive molt and feathers may not be replaced resulting in loss of overall feathers. Beak lesions typically show up late in the disease process and include abnormality in growth and shape with beak tissue that hemorrhages or sloughs. Secondary bacterial infections often occur.
Testing for PBFD includes blood sampling and biopsies. There is no available vaccine for PBFD at this time. PBFD is often likened to diseases that suppress the immune system and open the patient up for secondary infections. In the birds that do not succumb to acute PBFD, death is often the result of secondary bacterial or fungal infections.
Dr. Kerry Korber
Calgary Avian & Exotic Pet Clinic