ABSTRACTAvian encephalomyelitis is caused by an Hepatovirus and primarily affects chickens. Chickens of all ages are susceptible to the virus, but the nervous symptoms are manifested only in young chicks, between one to five weeks of age. During the last thirty years, avian encephalomyelitis appeared to be well controlled by breeder vaccination. However, the increase of the number of cases is causing concern in the poultry industry. In the present study, we performed a retrospective analysis of the cases presenting histological lesions compatible with avian encephalomyelitis in broilers. The evaluated cases affected broilers from one to 35 days old from the southern region of Brazil. Only cases with compatible microscopic lesions and associated with... |