Hereditary neuraxial edema in Hereford calves.

Twelve newborn Hereford calves from 8 herds showed extensor spasms upon stimulation and inability to rise. Neuraxial lesions consisted of widespread vacuolation interpreted as edema and seen chiefly in terminal portions of myelinated bundles and in gray substance containing heavily myelinated fibers. Genetic analysis of 2 of these herds indicated an autosomal recessive pattern of transmission tracing back to a single bull. The identity of the disease in all herds suggested that it had the same hereditary basis in all of them.