Cat Forum banner

1 - 8 of 8 Posts

·
Banned
Joined
·
5,533 Posts
Discussion Starter #1
I dont know if other people with hyperthyroid cats have come across the same problem, but my normally greedy cat pig has not really had too much of an appetite the last few days. He is eating but nothing like his usual amount (although treats still go down at record speed ... lol). I've not noticed any little brown numbers in his litter tray over the last two days ether. I've given him some vaseline as a laxative to see if his loss of appetite is due to being a bit bunged up.

He seems as bright as usual otherwise - gaining weight and looking content. Been eating his 'special treats' (bit of chicken/cheese/pill pockets with a little pink pill hiding inside them) pretty well.

Any thoughts? He is having his check-up at the vet on Saturday. He is currently on 5mg of Methimazole twice a day.
 

·
Registered
Joined
·
243 Posts
Don't have any advice for you, but just wanted to send you get well wishes. I hope Toby starts eating soon and stops worrying his mommy!
 

·
Registered
Joined
·
1,099 Posts
Has he been on the thyroid med long enough yet for the vet to recheck his bloodwork? Maybe the dose is a little high and needs adjusted. Methimazole can cause depression in cats as a side-effect.

Is he drinking as much water as usual? Do the skin pinch to see if he's dehydrated; that's a common cause of constipation. If he'll eat his food "soupy" (with water added), it can definitely help.
 

·
Registered
Joined
·
4,059 Posts
There are a number of issues that may cause inappetance, but I suspect that Toby's is a result of the methimazole. 10 mg daily is a MASSIVE starting dose that is likely to cause some nasty side effects, one of which may be hypOthyroidism (which will be determined ... or not ... with Saturday's bloodwork). In addition to hypothyroidism, methimazole overdose can cause digestive upset, diarrhea, vomiting, inappetance, facial itching, and/or liver and/or kidney damage. A much safer starting dose would have been 2.5 mg daily (1.25 mg daily for a cat with known renal problems).

Another possibility is that as the methimazole brought Tobey's T4 back into normal range, it unmasked pre-existing renal disease. Uncontrolled hyperT can mask renal disease so that it won't show up in bloodwork, but once the T4 is back in normal range, the renal problem WILL show up in bloodwork. Again, this will become apparent ... or not ... in Saturday's bloodwork. Just make sure your vet runs both a TT4 and a blood chemistry to check thyroid, kidney, and liver function.

The fact that Tobey had a very high starting T4 doesn't excuse such an absurdly high starting dose of methimazole. A high T4 simply indicates a lot of T4 hormone circulating in the bloodstream at the time of the test. It does not determine whether the excess T4 accumulated quickly due to a very hyperactive thyroid tumor, or whether the T4 accumulated slowly over a longer period of time due to a mildly hyperactive thyroid tumor. In other words, a very high T4 doesn't necessarily indicate the severity of Tobey's disease. Methimazole doesn't directly lower the amount of excess circulating T4 in the bloodstream. It merely reduces the release of new T4 from the thyroid glands. The excess circulating hormone is naturally utilized or excreted by the body over the period of a few weeks. After that excess hormone has been used or excreted, THEN the effect of the methimazole dose on T4 production will become apparent. That is probably where Tobey is now. He's had about a month to use or excrete the excess circulating T4, and the effects of the high dose of methimazole on his thyroid glands is now being expressed. If I were a betting person, I'd bet that he's significantly hypothyroid right now, and that's probably seriously affecting his appetite.

All of this will be clarified with Saturday's bloodwork. Make sure you get copies of all of Tobey's test results - both those from a month ago and the ones from this coming Saturday - so that you can keep track of his progress and see exactly how things are changing relative to his med doses. If you're so inclined, I'd be very interested in seeing his test results when you have them available to post here.

In the meantime, keep feeding him whatever he'll eat to prevent potential damage to his liver.

Laurie
 

·
Premium Member
Joined
·
1,681 Posts
I learn so much from the caring and knowledgeable folks here at CF! What a wonderful "back up system" this place is....

Hugs to you and Toby, Allie - your brave ginger boy should be better after tomorrow! Keep us posted! :patback

Fran
 
1 - 8 of 8 Posts
Top