THE EFFECT OF THYRO-PARATHYROIDECTOMY IN THE GOAT WITH PARTICULAR RESPECT TO CLINICAL EFFECTS AND CHANGES IN THE CONCENTRATIONS OF PLASMA CALCIUM, INORGANIC PHOSPHORUS AND MAGNESIUM

Abstract

SUMMARY Thyro-parathyroidectomy was performed on thirty-two goats. Hypocalcaemia and hypophosphataemia set in rapidly, but after a few days the plasma calcium and inorganic phosphate concentrations tended to stabilize. Thereafter they remained low and more than twice as variable as normal. The plasma magnesium concentration also fell initially but slowly returned to normal limits. These changes were not due to the loss of thyroid glands because thyroidectomy did not induce the same changes and the effects were not reduced by supplementation with thyroid hormone. Other changes were probably due to the low concentrations of plasma calcium, inorganic phosphate and magnesium. Young goats failed to grow normally and the density of the bones was reduced. Some goats developed cataracts. Although tetany occurred rarely there was a high incidence of a 'drowsiness syndrome' in which goats failed to eat, became debilitated and had to be slaughtered. Female goats failed to conceive, and abnormalities of gestation and lactation were observed.