Originally Posted by Barkingdog
But won't the treatment cause the cat to lose his appetite, I know this happen with people . That is want I would be worried about.
When cats have a high thyroid level usually one of the first signs that tips off the owner that something is off is the cat's appetite increases noticeably, especially when the thyroid hormone level is very high at more advanced stages.
The treatment will generally reduce the over stimulated appetite so sometime is may seem like they've lost it but with the hormone levels on their way back to normal levels so is the appetite.
When my cat had HyperT her appetite had increased a bit, during & after treatment she was back to normal & had no issues eating in clinic. Every cat is different however unlikely the treatment will cause them to stop eating all together. Some cats won't eat in strange environments but as this is done in hospital they will have appetite stimulants to administer if necessary.