Hyperthyroidism - doc says meds will not control it
My cat is 12. Back when he was 10, I noticed he was licking his fur off in a lot of places so I took him in. Well, they said it was allergic, gave him a shot, but because he only weighed like 8lbs the vet did blood work. The licking thing did end and his coat is beautiful, but the vet told me he had hyperthyroidism. We went on a methimazole treatment where I give him 1/4 of a pill twice a day. He had his bloodwork re-done a month later and all was well. 1.5 years later I took him in for blood work and the vet said his kidneys are working fine and thyroid is all within spec, etc. said he is A-OK
However, he has told me that this routine of giving him the pills won't help him with a long life. He said that he needs radiation therapy (said it'd cost me about $1000 to $1100) or else he prob will live max to around 17-18.
Otherwise, my cat is 100% solid. He plays, runs around, feels fine, looks great, no issues. He did put weight on after the methimazole and is like 9.2lbs now but he will never be a "big" cat.
So is all this true? Even if his bloodwork shows great and I take him in to re-check every year or so, should I really be taking him in for radiation right now?