Reply #2: Here's what I do with the cats I confirm as hyperthyroid:

[kestrel91316]

I put them on methimazole (anti-thyroid medication) for an initial trial period of several weeks, starting with a very low dose and gradually increasing, and rechecking the blood and urine tests to make sure there are no side effects developing and the kidney function is stable. If the cat can be well-controlled with methimazole and the kidneys are still ok then the cat is a good candidate for I131 treatment. Here in SoCal it involves a one-week stay at a special facility where the cats board in a lead-lined room to pee away the radiation. The treatment itself is one simple injection of I131. Simple, easy.......some followup blood tests to verify a cure, and voila! Not cheap........probably around $800-1000. But this is state-of-the-art treatment.

Surgery is what we used to recommend before the I131 became available. It is NOT considered a permanent cure because of occult thyroid tissue lurking all over the neck and chest. Long-term methimazole can be done, but there is the ongoing expense of blood tests to make sure sll is still well. And it has a risk of side effects.

I have a patient that can't take methimazole (he's hypersensitive to it and many other things) and because of existing kidney dysfunction he is not a candidate for I131 or surgery. So he is essentially screwed. He is ok for now, but will eventually waste away.