The effect of induced hypocalcaemia on the cardiac output and blood pressure of dairy cattle.

A mean reduction of plasma calcium level to 51 per cent of normal infusion of 4.7 per cent Na2EDTA solution into four cows was associated with a mean reduction of 48 per cent in cardiac output. Hypocalcaemia sufficient to produce sternal recumbency in a further four cows resulted in a highly significant fall in the mean arterial blood pressure, which returned to normal immediately after treatment with an intravenous infusion of 350 ml of 32.5 per cent calcium borogluconate.