The polyoma virus of pet birds belongs to the family Papova virus, the same group of viruses that causes benign skin tumors (warts) in birds. Polyoma virus can cause benign feather lesions in birds (the so-called French molt) or acute death.
How do birds get polyoma virus infection?
It is not fully known how the virus is spread. Infected but asymptomatic adult birds intermittently shed the virus through feather dust, droppings, eggs, and crop milk used to feed offspring. It is unknown how long it takes from the time of infection until death (if it occurs); however, death may occur anywhere from 15 days after birth (e.g. budgerigars) to 140 days (e.g. larger parrots).
What are the signs of polyoma virus infection?
There are different strains of the virus that can cause different clinical signs. Some birds recover from the infection but are left with abnormal feathers (French Molt). Other birds die quickly with no clinical signs. Still others may show abdominal enlargement, hemorrhagic areas under the skin, and tremors. Mortality can be high, reaching 100% in birds less than 15 days old. Birds that recover probably remain carriers of the virus and can shed it despite not showing signs of illness.
How can I tell if my bird is infected?
Birds, especially baby birds, die quickly and should be examined by a veterinarian. Both sick and healthy birds can be tested using a specific DNA probe of a cloacal swab, easily obtained by the veterinarian.
My bird is healthy. Should it be tested?
This can best be decided by your veterinarian. However, if you plan on purchasing another bird, both should be screened for polyoma virus, as either or both birds can be carriers without showing signs.
How is polyoma virus treated?
There is no definitive treatment for birds with polyoma virus infection other than supportive care. Birds with mild hemorrhaging might benefit from vitamin K injections. Often, the disease progresses so quickly that no treatment will be effective.
Can I prevent polyoma virus infection?
Manual removal of droppings and feathers followed by careful disinfecting of the environment can help reduce viral contamination of the environment. The DNA probe test should be done on currently owned birds and new birds before they are put together. Because birds can shed the virus intermittently, several negative tests are needed to be somewhat certain that a bird is not a carrier. A polyoma virus vaccine is being developed that may prove effective.