Definition:

Polyomavirus is a disorder that caused a bird's tailfeathers and flight feathers to develop improperly. In severe cases of polyomavirus, the feathers may not develop at all. Birds that are affected by the virus may appear weak, bruise easily, and experience appetite loss. Other symptoms include an enlarged abdomen, paralysis, and diarrhea. Polyomavirus can be fatal, so birds suspected of infection should be seen by an avian veterinarian promptly.