A progressive spinal myelinopathy in beef cattle.

Ataxia of the hind limbs in nine calves was associated with degenerative lesions in spinal white matter and neuronal chromatolysis in red nucleus, spinal grey matter and various nuclei of the medulla oblongata and cerebellum. The clinical signs and lesions were similar to those observed in enzootic ataxia of red deer and occurred predominantly in calves of the Murray Grey breed. The pathogenesis appears to involve a primary defect in central nervous system myelin with progressive myelin loss primarily in the spinal cord.