Progressive ataxia` in a Charolais steer in New Zealand

Signs of progressive central nervous system disease in cattle aged 2 years and older should alert farmers and veterinarians to consider the possibility of bovine spongiform encephalopathy (BSE). Government veterinarians routinely assess all livestock slaughtered in meat plants in New Zealand for signs of any nervous disorder, including abnormalities of behaviour and mental state and abnormalities of posture and gait. In April 2001, a 2-year-old Charolais steer sent for slaughter was observed at antemortem inspection to have bilateral nystagmus and a generalised whole body, fine tremor. As these signs fitted the criteria for the BSE surveillance programme (Belton 2001), after slaughter, the skinned head was sent to the Ministry of Agriculture and Forestry, Biosecurity approved, veterinary diagnostic laboratory in Palmerston North for brain removal. No macroscopic abnormalities were detected in the brain. Histopathological examination of haematoxylin and eosin stained sections of the brain revealed…