The Prognosis for Hyperthyroidism in Cats on Tapazole

The vet just called with bad news. Your beloved KitterKat is hyperthyroid. Now you're wondering how much time you have left with your aging friend. Will you able be to give him his medicine? Will his quality of life suffer? How long can cats live with this dreaded disease?

Take a deep breath and wipe away the tears. Although hyperthyroidism in cats is serious, the prognosis for hyperthyroid cats on Tapazole is generally very good.

A Common Disease

Feline hyperthyroidism is the single most common endocrine disorder of cats, according to the veterinarians at Gulf Coast Veterinary Specialists in Houston. “It’s been reported that up to 31 percent of all cats” have thyroid adenomas (benign tumors), the doctors say.

Hyperthyroidism occurs when a benign growth in the thyroid gland causes the gland to produce too much of the hormone T4. The excess T4 causes the cat’s entire body to shift into overdrive, taking a toll on all the organs, especially the heart and kidneys.

Treatments for Hyperthyroidism

The most common treatment options for hyperthyroid cats are medication and radioactive iodine therapy. One radioactive iodine treatment cures most cats.

For cats who will be treated with medication, methimazole (trade name Tapazole or Felimazole) is usually the drug of choice. To avoid side effects, veterinarian Wendy C. Brooks recommends starting at a low dose and gradually working up to the full therapeutic level.

The newest treatment option is reduced-iodine prescription food. The jury's still out on this treatment, though, and veterinary endocrinologist Mark Peterson raises many questions about its safety over the long term. He recommends not using it.

Forms of Tapazole

Tapazole is available as tablets. But if KitterKat is difficult to pill, a compounding pharmacy can make his medicine into a flavored liquid or a gel that you'd rub inside an ear tip.

Some tricks for giving a cat pills include hiding the medicine in a “sandwich” of soft moist treats, dissolving it in a little bit of vanilla ice cream or plain yogurt or crushing it into a bite of tuna. You can also buy cat treats shaped to hold a pill.

Prognosis for Hyperthyroid Cats

Even the experts can’t say exactly how long a hyperthyroid cat treated with Tapazole will live. Writing for, veterinary endocrinologist David Bruyette said the “median reported survival time” of a cat treated with methimazole is 24 months. But many cats live much longer.

If you make sure KitterKat gets his medicine and is checked by the vet often, he could have a wonderful quality of life and be with you for a very long time.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

the nest