Maple syrup urine disease in five hereford calves in ontario.

Five newborn grade horned or polled Hereford calves in Ontario exhibited the clinical signs characteristic of hereditary neuraxial edema, namely, inability to rise, and hyperesthesia with extensor spasms upon tactile or auditory stimulation. Histologically, there was widespread spongy vacuolation in both white and gray matter in the brains of all five calves, especially in the midbrain, brain stem, and cerebellum. Amino acid analysis of formalin-fixed cerebral tissue of three calves demonstrated an amino acid composition consistent with a diagnosis of branched chain keto acid decarboxylase deficiency. This condition has been recently reported in Hereford calves in Australia; it is characterized by the delayed onset of neurological signs and severe lesions of status spongiosus, and has been considered analogous to maple syrup urine disease of children.