Lethal toxicosis in 11 calves with hyperkeratosis

During a period consisting of 28 months (1984-1986), 11 calves were affected in one small farm rearing Japanese black beef cows. Clinical signs, which developed gradually within several days to 3 months after birth, include the following symptoms; namely, marked hyperkeratosis of skin, ulcerative nodules and white collard raised "plaques" brought about on the mucosa of the mouth and lips and especially on the tongue,a-febrile diarrhea, marked retarded growth and so on. Any treatments had no effects. The calves showed anorexia, poor activity, gradual depression and terminal paresis. They died or were sacrificed in 77f to 252 days old. All the 6 dams were diagnosed to be in good health, no special abnormality was noted in blood examination, being good and well in fertility and parturition. They had nothing in common in genetics, age and parturition parity. Four sires were employed in the breeding of the affected calves. Blood examination of the calves showed low total plasma protein content and severe liver dysfunction. Pathological findings include hyperkeratosis of the skin and tongue, esophagal ulcers, hemorrhage or ulcer of the abomasum, gallbladder enlargement, multiple focal grayish-white plaques observable in the cut surface of the liver, and renal degeneration. Histopathological findings include the marked hyperkeratosis of the cornified layer in the epithelium of the skin and tongue, spinocellular degeneration, proliferations of the interlobular connective tissue and bile ductles in the liver, and dilatation of the distal renal tubules and collecting tubules. No suggestion of any genetic or infective causes was to be obtained by the above mentioned findings. Some toxicosis was strongly suspected as a cause, and there was a high similarity between this disease and chlorinated naphthalene toxicosis. After all, this disease was fixed to be an extraordinary one affecting only calves with marked shin lesions