I would wait and see what John says, he's dealt with a thyroid piggy very successfully in the past so knows what he's dealing with.
I would also be hesitant to operate on an almost 5 year old if it could be avoided. I don't recall him ever saying that Haven couldn't be on thyroid meds long term.
It is kind of a long story but my Cash was diagnosed with hyperthyroidism and a lump under his chin began appearing, he underwent surgery at the hands of a very experienced piggy savvy vet to remove it because it was growing too quickly to try and combat with thyroid meds. Sadly he did not survive the op and passed just as the final stitches were being put in. Its a bit too hard to summarise briefly so I'm just going to copy and paste about the analysis of the removed lump from my original thread as I think it could have implications for your decision to operate or not.
"The lump was mainly cystic but with a large area of abnormality which the lab thought could be hyperplasia but was more typical of an adenoma or benign tumor. Apparently in cats these tumors are usually the functional tumors that produce thyroid hormones so this matches his prior diagnosis of hyperthyroidism. The main thing to take away is that thyroid problems of this kind can cause changes in the heart muscle- though obviously no one can say if this is why he went into cardiac arrest. Though there were no medical signs of his heartbeat or activity being irregular he did sleep very deeply and start off a bit slow whenever he woke up so I'm thinking perhaps it was the case.
Then again he was put under GA for his blood test when he was in a much worse state weight-wise and he came out of that fine. So who knows.
Part of me wishes we had tried thyroid meds first just to see if they'd made any difference before operating but the rate at which the cyst was growing meant it would have soon been impacting on his quality of life... But whats done is done, and sadly these things happen.
I think for anyone with potential thyroid pigs in the future its important to be cautious and aware of the implications of thyroid activity on the heart."
I didn't want to link to Cash's experiences at first since someone had already provided you with Haven's hyperthyroidism story, which contains mostly all the same details and a happier ending! Here they are though if you want a nose.
Cash thread 1:
Healing Vibes For My Little Cashman!
Cash thread 2:
Advice Needed Please! Cash Has A Lump
