Avian polyomavirus infections in Amazon parrots

According to the avilable literature budgerigars are the most susceptible to being infected with avain polyomavirus (APV), whereas this infection is very rare in Amazon parrots. Although the same virus is responsible for the disease, clinical symptoms in the Amazon parrot are considerably different than those observed in budgerigars. APV is transmitted primarily bird-to-bird but it is also thought to be transmitted via the egg. Many affected young amazon die, while most infected adult birds develop lethargy, poor appetite and diarrhoea, with the surviving birds developing antibodies to the virus. However, despite the common misconception, that adult birds are more resistant, the adult amazon are readily susceptible to infection, can become ill and some may die. The main clinical symptoms of APV infection in the amazon parrot include hepatomegaly, ascites and hydropericardium. Necropsy often show spleno- and hepatomegaly with irregular red and yellow mottling of the liver, while histopathological examination present pathognomomic lesions as multifocal necrosis in the liver and kidney, enlarged nuclei and enlarged amphophilic intranuclear inclusions in the liver, kidney and spleen. Procedure against APV infection in an outbreak requires vaccinating the adults and neonates to stimulate flock immunity as well as cleaning and disinfecting the contaminated facility.