Numerous viruses have been associated with disease in various avian species; however, the extent to which birds maintained in captivity are infected is not well understood,1 and may be underestimated. Viral diseases diagnosed in birds by the Zoo/Exotic Pathology Service were reviewed. The material was from case submissions that included complete necropsies as well as limited fixed-tissue samples. Diagnosis was made by lesion type and in most cases the finding of inclusion bodies typical for the virus. In some cases, specific probes were used to confirm the diagnosis. Diseases caused by adenovirus, calicivirus, circovirus, flavivirus (West Nile), herpesvirus, papillomavirus, paramyxovirus, polyomavirus, poxvirus and togavirus (WEE) were definitively diagnosed. Cases of probable parvovirus were seen, and a large number of cases of proventricular dilatation disease (a probable viral entity) were diagnosed. In addition, cases of probable viral disease (exact cause not determined) were seen.
Viral disease was found in 15 avian families. The most common viral diseases diagnosed were circovirus (61.2% in Cacatuidae), polyomavirus (50.3% in Psittacidae), proventricular dilatation disease (63.23% in Psittacidae), herpesvirus (89.9% in Psittacidae), poxvirus (48.5% in Fringillidae) and adenovirus (87.1% in Psittacidae). The primary reason for the predominate occurrence of viral diagnoses in Psittaciformes is considered to be the large number of these birds in aviary and pet situations, and the willingness of their owners to spend money on diagnostics.
1. Ritchie BW. An overview of viruses. In: Avian Viruses, Function and Control. Lake Worth, FL: Wingers Publishing Inc.; 1995:1–25.