Porcine focal symmetrical poliomyelomalacia.

An acute afebrile paretic condition was diagnosed in 16 of 100 feeder pigs between eight to ten weeks of age. Nine pigs died acutely and seven pigs were euthanized. Macroscopic lesions in the ventral horns of the cervical, thoracic, lumbar and sacral segments of the spinal cord consisted of focal, bilateral, grey depressed areas. There was a bilateral symmetrical focal poliomyelomalacia histopathologically characterized by microcavitation, endothelial and glial cell proliferation and infiltration of eosinophils. Clinical and pathological findings resemble spontaneous and experimental lesions associated with acute nicotinamide deficiency and selenium toxicosis in swine.