Laminitis and dermatitis in heifers associated with excessive carbohydrate intake: skin lesions and biochemical findings.

The effects of a sudden addition of a large quantity of readily fermentable carbohydrate to the feed ration of pregnant heifers are described. Clinical and pathological changes caused by the resulting disease were confined to the digits and skin. The 4 acutely affected heifers were reluctant to get up or move (group II). They tended to lie down or stand with feet bunched together and the back arched, often shifting weight from limb to limb. They walked stiffly with great tenderness and pain in the digits. Extreme pain was noticed when the digits were examined. In 4 of 8 heifers, separation of the sole at the heel, with leakage of exudate, and under-running of the sole were observed. Necrotic dermatitis of the legs, alopecia and hyperkeratosis of the tail were noticed in all 8 heifers. Skin lesions appeared simultaneously. Four of the heifers (group I) recovered, and the other 4 (group II) were sent to slaughter. No post mortem examination was performed. The biochemical findings revealed a significantly higher concentration of total serum globulins and sodium, and increased activity, in CK, LDH and AST. A significantly decreasing pattern was noted in blood urea concentration, cholesterol, triglycerides, albumin and calcium. No significant differences among the various groups were found in the activities of amylase, GGT, and concentration of creatinine, total bilirubin, inorganic phosphorus, magnesium and potassium.