It is a viral disease that has been found to infect many species of psittacine birds (parrots) and is widespread throughout the United States as well as most countries of the world where psittacine birds are raised. It is a relatively common cause of acute death in young birds less than 16 weeks of age, where infected birds can die without showing any signs or illness or die shortly after demonstrating depression, lack of feeding reflex, crop slowdown, feather abnormalities, and/or bleeding beneath the skin. In adult birds, polyomavirus can cause lethargy, lack of appetite, regurgitation, diarrhea, dehydration, and sometimes death, but in general the disease is not as severe when it infects mature birds. Macaws, eclectus, lovebirds, caiques, and conures are particularly susceptible.
Diagnostic tests can be performed on your bird’s blood and swabs of the cloaca (vent area). These sensitive tests can determine if your bird has been exposed to polyomavirus in the past and/or is possibly shedding the virus from its body. A bird that is polyoma positive and thought to be shedding virus is considered infectious to other birds. Some birds that have been exposed to polyomavirus will develop a mild illness and then return to full health. These birds, however, may shed the virus and expose susceptible birds. The period of time that these recovered birds shed virus varies from case to case; however, most infected birds stop shedding virus and revert to a negative status within six months.
The number one thing you can do to protect your bird is to prevent exposure to other birds that may be harboring the virus. This means keeping your bird away from pet shops, bird marts, and bird shows where it may be exposed to strange birds of unknown health status. Whenever you buy a new bird, it is best to test this bird for polyomavirus and keep the bird in an isolation area, away from other birds in the household, for a period of at least 60 days. In addition, if you breed birds, it is ideal not to mix species in the same aviary. In other words, don’t raise conures and lovebirds in the same room/building as macaws and eclectus.
Vaccinating your bird against polyomavirus needs to be considered on a case-by-case basis. Certainly anyone who is breeding pet birds should strongly consider vaccinating all adult birds in the aviary, as well as all juvenile birds at 9 weeks of age and again at 12 weeks. If you own a pet bird, vaccination should be considered if your bird is routinely exposed to other birds. Examples of where your bird may be exposed to other birds include visits to pet shops for nail and wing trims, bird shows or marts where other birds are sold or displayed, and boarding at a facility where multiple birds are kept. If these scenarios apply to you and your bird, then vaccination is strongly suggested. Adult birds should initially be vaccinated twice at three-week intervals, one year later, and every three years thereafter to maintain protective immunity.