Enzootic calcinosis in 16 cows in the Unterengadin valley in Switzerland

Enzootic calcinosis was diagnosed in 16 cows, which originated from 6 dairy farms located in the Unterengadin valley in Switzerland between 1,402 and 1,650 metres above sea level. During the winter, the cows were fed haylage, which contained up to 50 per cent golden oat-grass (Trisetum flavescens), and hay and grain. The first symptoms of enzootic calcinosis were noted in March 1998, when some of the cows developed locomotor abnormalities. Additi onal cases were diagnosed during the following three months. The most impor tant clinical findings were decreased milk production, weight loss, frequen t recumbency, difficulty in rising, kneeling while rising and feeding, stil ted gait, arched back, shifting weight from one foot to another and relucta nce to remain standing after being roused. Of the 16 cows, 5 had elevated c oncentrations of serum calcium and 10 had decreased concentrations of serum magnesium. All cows had normal of decreased concentrations of serum phosph orus, because the feeding of haylage containing golden oat-grass had been d iscontinued two months previously. In all of the cows, the most important postmortem findings were severe calc ification of the aorta, iliac artery, brachiocephalic trunk and pulmonary a rtery.