Hello we have a 12 year old much loved cat who developed hyperthyroid last year. He is on Felimazole But the vet just recentlly raised the dose to 20 mg a day..lower doses just are not controlling it. He briefly mentioned radioactive iodine as an option, which is costly and also horrible imo because of the long quarantine period after the injection, but considering the annual cost of repeated vet visits, two kinds of meds, and testing, we are beginning to look at the radioactive iodine treatment as an option. I have researched it and it does work as far as all I could find on line, and also what the vet told me. I have heard and read about other alternatives such as vitamin supplements, vitamin e treatment, and so forth. I'm curious if anyone else has experienced this and what you have done to treat and what the results were. Our cat seems happy enough, he still goes out, plays, purrs. But he is a lot weaker and a bit lethargic, his TE is frequently lowered on both eyes, and he is very clingy now. Vet says he is ok now but it is only a matter of time before he severely declines, so we are researching everything we can. Please help, if you can.