Hyperthyroidism in Elderly Cat

[thatmoody]

Quick question for those who have used methimazole transdermally in cats. If I don’t have a thyroid (had it ablated completely when I was 16), would this be an issue for me?

[Simkie]

The thyroid blocking effects of methimazole occur actually in the thyroid itself, so without an active one, you’re not at risk there.

https://www.ncbi.nlm.nih.gov/books/NBK545223/

However, methimazole also interferes with the conversion of T4 to T3. If you’re taking levothyroxine as thyroid replacement, that is T4, and your body converts that to the active hormone, T3. That’s not a process you want to limit. This is one area where methimazole could harm you.

Methimazole: Thyroid Uses, Side Effects, Dosage

Methimazole also does have several potential side effects or risks of adverse effects. You don’t want to sign up for those.

https://www.ncbi.nlm.nih.gov/books/NBK545223/

Definitely handle with care. You still have potential for risk, even without an active thyroid.

[thatmoody]

This is very helpful, thank you. Yes, I take synthroid and don’t want anything to interfere with that!

[rockymouse]

Does the liquid form of medicine go on their food? Our 11yo cat has become voracious and it occurred to me that she’s probably hyperthyroid. I’ll of course take her to the vet to confirm, but I’m already thinking ahead to medicating her. She’s survived a rattlesnake bite and an attack from an owl/eagle/hawk that resulted in an amputated tail. Unsurprisingly, she’s now
very difficult to even get into a cat carrier and not at all a candidate for pilling meds.

[quietann]

The transdermal meds are by far the easiest. Yes you need to catch the cat and hold it but the whole process takes about 5 seconds, especially if you do the “ear flap taco.”

[Larbear]

@ThreeWishes

HELP. Eddie has been on his transdermal meds for 1 week. Two days ago he became quieter. Less interested in food. I’ve tried everything. Garbage food. Expensive food. Human food. He eats very little. Maybe a 1/4 to barely 1/3 of what’s offered.

I saw that he’s back eating again but if he goes off eating before he gets his levels checked, it could be that the dose is too high.

My old kitty man was hyperT but unlike the usual hyperT cats, his appetite tanked. Talk about stressful!

[ThreeWishes]

I thought the same thing. So I dialed him back to one click twice a day instead of two. His belly settled down and he he stopped sleeping like
The dead. Now he’s much more normal. Appetite is regular instead of famished and his energy level is calm.