Identification of avian bornavirus in a Himalayan monal (Lophophorus impejanus) with neurological disease

Abstract

A one-year-old male Himalayan monal (Lophophorus impejanus) was presented for veterinary attention with a history of chronic wasting, weakness and ataxia. The bird died, and post-mortem findings included mild non-suppurative encephalitis and degenerative encephalopathy, lymphoplasmacytic myenteric ganglioneuritis (particularly of the proventriculus), and Wallerian degeneration of the sciatic nerves. Avian bornavirus (ABV) was identified in the brain by immunohistochemistry and reverse-transcriptase polymerase chain reaction. Sequencing of the reverse-transcriptase polymerase chain reaction product indicated the presence of ABV genotype 4, which is generally associated with disease in psittacine birds. Subsequent to the death of the pheasant, ABV genotype 4 was identified at autopsy from a juvenile white-bellied caique (Pionites leucogaster) in the same collection. We hypothesize that the pheasant became infected through contact with psittacine birds with which it shared an aviary. We believe this to be the first reported case of natural ABV infection in a bird in the Order Galliformes.