LAMINITIS IN YOUNG DAIRY CALVES FED A HIGH STARCH DIET AND WITH A HISTORY OF BOVINE VIRAL DIARRHEA VIRUS-INFECTION

Six of the 33 calves born in a Swedish dairy herd during a period of f our months developed laminitis when they mere eight to 12 weeks old, T he clinical signs included difficulty in rising, a stiff gait, overgro wn claws and haemorrhages in the sole horn, Samples of blood were take n from four of the calves when they had shown signs of laminitis for t wo to seven weeks; the serum concentrations of calcium, phosphorus and vitamin D-3, the activities of aspartate aminotransferase and glutath ione peroxidase, and the patterns of serum proteins were within their normal ranges. The feet of the same four calves were examined after sl aughter; the third phalanx of each calf was rotated and its distal end osteolytic. Histologically there was separation and degeneration of t he squamous cells of the white line, and thromboses and vasculitis in the fine vessels of the cerium, Four of the six affected calves were p ersistently infected with bovine viral diarrhoea virus and one had ant ibodies against the virus. From six weeks of age the calves had been f ed rye wheat, a hybrid seed rich in starch, and this may have contribu ted to the outbreak of laminitis.