The impact of microbial agents in psittacine birds with and without clinical signs. 2: Virus isolations

The study involved determining the prevalence of viral infections in health y and diseased psittucines and investigating,whether virus infections is as sociated with a particular species or with specific clinical signs. Over th e 18 month period from October 1992 to March 1994, 2171 swabs and 399 tissu e samples were taken for virological examination from 1077 psittacines, The birds comprised patients of the Clinic for Birds and Reptiles, University of Giessen and members of three private bird collections. Retrospective dat a and clinical signs were recorded for all birds. Viruses were isolated fro m 42 birds. These comprised: ten paramyxoviruses of serotype 1, 28 herpes v iruses of serorype 1 of Pacheco's parrot disease and four pox viruses. No s ignificant prevalence of virus infection was found in any species. No typic al clinical signs were observed in psittacines infected with paramyxovirus. Clinical signs indicative of a viral aetiology were frequently observed in birds infected with herpes or pox viruses. Herpes virus infection was asso ciated with lethargy and digestive tract disorders. Pox virus infection was associated with skin, mucosal and eyelid lesions. Psittacines with non-spe cific clinical signs and those which appear healthy can, however; carry and excrete these viruses. This particularly important with respect to the tra nsmission of contagious infections such as Newcastle disease.