Feline hyperthyroidism

Re: Feline hyperthyroidism

Utlendigur — Thu, 21 May 2009 22:25:48 GMT

We've had one cat that was stable on neomercazole (generic) for years after reacting to felimazole. Swapped to vidalta when that became available, and the cat rapidly destabilised - so has gone back to generic and doing ok. We've had a couple of cats which failed to reduce T4 levels even on very high doses (of whichever we were using), and if I remember thyroidectomy, one of which had what looked like miliary mets throughout its lung fields on xray so possibly a thyroid carcinoma?

My own geriatric cat (of course - she belongs to a vet!) developed a variety of side effects on felimazole, vidalata and finally generic neomerc - vomiting, anorexia (lost 200g prior to diagnosis, but nearly 1kg after starting Tx!), ventral oedema, retinal detachment due to hypertension etc. Eventually gave up and removed her thyroid despite the GA risks (mainly risks to the nurses - she has a bit of an attitude problem)

Re: Feline hyperthyroidism

ms1083 — Thu, 21 May 2009 20:33:16 GMT

p.s. seen no side effects of either vidalta or felimazole.

Re: Feline hyperthyroidism

ms1083 — Thu, 21 May 2009 20:31:40 GMT

We have had great problems with carbimazole (Vidalta). When it came on the market I thought it was a brilliant idea being once a day and started a lot of cats on it. The owners were not crushing the tablets and most were tableting the cat rather than putting in on the food.

Out of the 26 cats in the practice we started, only 3 are still on it and of them it is only definatly working on 1! The majority of the others have gone onto felimazole and doing very well. Blood results showed the vidalta was reducing the t4 levels but nothing like enough to reduce the signs of hyperthyroidism - we gave it 2 months on vidalta before checking blood levels.

I have now stopped using carbimazole as it is a rewarding condition to treat and very frustrating when the treatment does not seem to work. Our rep tells us that most practices have no problems. As hyperthyrodism seems to be geographical could there be almost different strains???

Re: Feline hyperthyroidism

Holly Lee — Sat, 16 May 2009 16:05:59 GMT

Haven't found a huge difference myself but have known colleagues to have commented that with vidalta they seem difficult to stabilise even on the higher dose and are needing much higher doses than expected.

Re: Feline hyperthyroidism

scarlet — Sat, 16 May 2009 11:16:47 GMT

agree with kevin - seems to work well - and often at low doses ie 10mg. we always start on the lowest dose ,as renal failure is often masked by hyperthyroidism , so we like to start carefully and increase dose depending on follow up blood tests. the only problems we encounter are administration (if cats wont take it whole), and cost (compared to felimazole)

Re: Feline hyperthyroidism

Kevin Castle — Mon, 27 Apr 2009 15:15:13 GMT

We've had exactly the opposite. We had a lot of cats reacting to Felimazole (dermatitis, lymphadenopathy, blood disorders and many vomiting) and have had no reactions since switching to Vidalta (long-acting form). We've had at least 30-50 cats on Vidalta and it seems to be working really well. Only issue has been a small number of cats that will not take it in food nor allow oral dosing by the owner.

Re: Feline hyperthyroidism

Stephen Ashman — Fri, 24 Apr 2009 19:14:45 GMT

We've had problems with vomiting in most of the cats we have started on it, so in the majority of cases they have been swapped onto felimazole after a fairly short period of time.

Re: Feline hyperthyroidism

Gillian Mostyn — Fri, 24 Apr 2009 16:36:07 GMT

We've found it very efficaeous - subjecively speaking of course. Client compliance improves and it does seem to bring down the T4 to normal levels pretty quickly in the cases we see.