Clinical, laboratory and histopathological findings are described in ten Braunvieh calves with Spinal Dysmyelination (SDM). Characteristically, immediately after birth the animals were normally alert but remained in lateral recumbency with opisthotonus, spastic hind limbs, partially increased spinal reflexes and were unable to stand or support themselves. Histological examination of the spinal cord revealed a bilateral symmetrical reduction of myelin. Means of differentiating between SDM and other conditions, in particular spinal muscular atrophy (SMA) are discussed.