Rabies outbreak in buffaloes in Rio Grande do Sul, Brazil

This report aimed to describe the clinical, epidemiological and pathological aspects of an outbreak of rabies in buffaloes in Rio Grande do Sul (RS), Brazil. Seven out of 41 buffaloes from the same farm became fatally ill; they showed the clinical signs of ataxia, ascending paresis, and paralysis of the limbs. During necropsy, marked hyperemia of the leptomeningeal vessels, and severe distention of the urinary bladder were noted. Histologically, there were indications of nonsuppurative meningoencephalitis and ganglioneuritis with intracytoplasmic and eosinophilic inclusion bodies in the neurons. The fluorescent antibody test was positive for rabies. Viral antigens were also detected by immunohistochemistry (IHC) in sections of the cerebellum. These results allowed for the definitive diagnosis of rabies, which is uncommonly reported in buffaloes.