Feline thyroidectomy. A comparison of postoperative hypocalcemia associated with three different surgical techniques.

Three bilateral thyroidectomy techniques used in 41 hyperthyroid cats over a 7 year period were compared for rates of postoperative hypocalcemia. Extracapsular dissection of the thyroid glands resulted in an 82% rate of postoperative hypocalcemia. An intracapsular dissection technique produced a 36% rate of postoperative hypocalcemia. The incidence of postoperative hypocalcemia was reduced to 11% when bilateral thyroidectomies were done asynchronously (staged), 3 to 4 weeks apart. Immediate postoperative treatment with dihydrotachysterol did not reduce the incidence of postoperative hypocalcemia. Because the incidence of hypocalcemia did not differ significantly between intracapsular and staged intracapsular dissection, the authors concluded that staged bilateral thyroidectomy in hyperthyroid cats had limited benefit over simultaneous bilateral thyroidectomy.