The gold-standard treatment for hyperthyroid cats is radioactive iodine therapy (RAIT), a one-time permanent treatment. When RAIT is not an option, other treatments include daily oral or transdermal anti-thyroid medication, dietary iodine restriction, and surgical removal of the thyroid gland. Each option has risks and benefits.
RAIT is not legally available at primary veterinary hospitals in Japan, so Japanese researchers compared the survival times of cats who underwent thyroidectomy to cats who were treated with the medication methimazole.
While thyroidectomy carries anesthesia-related and other potential risks, when successful, cats no longer require medical therapy. Methimazole therapy must be administered daily, and periodic bloodwork is required to assure efficacy and avoidance of side-effects.
This study showed that cats that underwent thyroidectomy had longer survival times than cats treated medically. This may be partially due to problems with dosing methimazole but still suggests surgery is the “next best” option for hyperthyroid cats.
Naito, E., et al. “Comparison of survival times of cats with hyperthyroidism treated with thyroidectomy or methimazole at a primary care hospital in Japan.” American Veterinary Medical Association, Vol. 262, Issue 11.
