Surgical Treatment of Feline Hyperthyroidism. Results of 85 Cases

Birchard S.J., Peterson M.E. and Jacobson A.

J Am Anim Hosp Assoc, 1984. 20: p.705-709.


The use of thyroidectomy was evaluated as treatment in 85 cats with hyperthyroidism. Based on thyroid scan and surgical findings, 32 cats had a unilateral thyroidectomy, whereas 53 had bilateral thyroidectomy. Atrial and ventricular dysrhythmias developed in nine (10%) of the cats during surgery. Eight cats (9%) with severe hyperthyroidism died during or immediately after surgery. Post-operative complications included hypoparathyroidism in four cats, Horner’s syndrome in one, and voice change in one. In the three cats with hypoparathyroidism that were successfully managed with calcium and vitamin D, the parathyroid hormone deficiency was transient and treatment was discontinued after two to six months of therapy. Postoperatively, serum thyroid hormone concentrations fell to normal or low concentrations within 48 hours of surgery in all cats. Relapse of hyperthyroidism occurred in four cats 8 to 44 months following bilateral thyroidectomy; these cats were again successfully managed with either repeat thyroidectomy or radioactive iodine therapy.