Psittacine Beak and Feather Disease (PBFD or PsCV)
By Paul Skellenger
Psittacine Beak and Feather Disease is caused by a virus (Psittacine Circovirus) and in many ways is the avian equivalent of the human AIDS virus. Birds suffering from this disease can show abnormal feather growth (known as feather dystrophy) and have necrosis of the beak - hence the name. The virus is capable of suppressing the bird's immune system to the point that they become debilitated and susceptible to secondary infections that ultimately kill the bird. This is truly a devastating disease and is highly contagious.
Many birds infected with PsCV develop a transient infection that the bird's immune response effectively clears. In birds that do not mount an effective immune response, disease can be sudden and devastating or more chronic and insidious. Old World parrots that become infected usually die, although some New World parrots that become infected will eventually recover. Infected Lories are usually less severely affected and can have feather abnormalities, but recover.
It is recommended by VeterinarianCare.us that all birds be tested for PsCV. There are two types of Psittacine Circovirus, PsCV 1 and PsCV 2. A bird infected with PsCV 2 has a greater chance of recovery compared to those infected with PsCV 1. It should be noted that some PsCV infected psittacines of South American descent have spontaneously recovered from the disease.
A positive test in a bird with no feather abnormalities indicates that the bird has been exposed to PsCV and that viral nucleic acid is present in the blood. This bird must be retested in 90 days for PsCV-1 and 180 days for PsCV-2. If the bird is still positive then, this indicates that the bird is either subclinically infected or that the bird is being repeatedly exposed to the virus. Subclinically infected birds can develop feather lesions at some future date. If the bird is negative when retested, this indicates that the bird was transiently infected and that the bird's immune system was able to clear the virus from the blood. Birds with normal feathers that have cleared an infection should be considered resistant to subsequent infection and disease. Most birds that are exposed to the PsCV will have viral nucleic acid present in their blood for a brief period.
If a bird with feather abnormalities is found to be positive for PsCV 1, PsCV 2 or any variant of circovirus, the bird should be removed from the area as quickly as possible. Virus-infected birds with feather abnormalities shed large concentrations of virus in their feather dust which can be easily carried to other birds by the wind or on clothes, skin or hair. All areas, supplies, and equipment that could be contaminated with feather dust should be repeatedly cleaned and disinfected.
Birds that are recovering from PsCV will test negative for months before all of the affected feathers (the cells of which will retain PsCV until molted) are replaced during the molting process with new uninfected feathers. As long as dystrophic feathers or their associated dust is present, the bird should be considered infectious.
About the Author
Dr Paul Skellenger is the Veterinarian for Veterinarian Care. US and has over 20 years in Veterinarian medicine and experience with bird care. For additional information you can contact one of our Veterinarians in your area. You can also contact the doctors and staff at Research Pet and bird Hospital at Research Pet and Bird Hospital, 11679 Research Blvd., Austin, Texas 78759. Phone 258-2577, Fax 346-4571, Email firstname.lastname@example.org or go to our website at researchpet.com.