Felimazole
Felimazole tablets are given to control hyperthyroidism in cats
I am writing this article about felimazole as my stats show my site is getting searches for that as a key word. Felimazole tablets are given to control hyperthyroidism. This is a common condition of older cats and is due to over-production of thyroid hormones from the cat’s thyroid glands. A pair of these glands is present in either side of the neck, but they are usually very small and difficult to feel. In hyperthyroidism, one or both glands become very much enlarged, often becoming easy to feel. Felimazole tablets contain the drug thiamazole which suppresses the amount of thyroid hormones released (called thyroxine, often known simply as T4, and triiodothyronine, known as T3). An enlarged gland will not shrink with treatment, but its activity will be controlled. There are 2.5mg tablets which are pink, and 5mg tablets which are orange, they are designed to be given directly into the mouth and swallowed whole. However this is very difficult with some cats so a “pill popper” might be useful.
Like all medication side effects are possible, mild side effects are not unusual, though the vast majority of cats show none at all, and thrive on treatment. The most common side effects are vomiting, going off food and becoming listless. Occasionally more serious side effects are seen and these can be quite varied. Some cats seem to feel itchy about their face and neck, they then scratch themselves and develop open sores and scabs on the head and neck. Other effects seen more rarely might involve the bone marrow, resulting in anaemia or abnormalities of the white blood cells and immune system. The mild side effects usually settle down after a short while and do not require treatment to be stopped. If more serious side effects are suspected, treatment should be stopped and veterinary attention sought.
In the UK felimazole is a prescription drug and so can only be obtained via your veterinary surgeon, I am not going to write on dose rates as this should be worked out by your veterinary surgeon following blood tests to work out the severity of your cat’s disease. Cats on this medication should have blood tests from time to time both to help your vet work out the dose rates and to check for side effects.
Scott
So wish i had seen this web site before about Femimazole and its side effects if so our Beloved cat Prince might have been still alive you hope and prey that your vet has all the knowledge but one must search for answers yourself if he cant seem to find an answer as to why hes not getting better but worse especailly as the cat was so difficult to get to take the pill he must have known it was making him worse cats intuition !!! he knew best all along and we wouldnt listen i am so angry with myself for not trusting our beloved pets wishes no pill please.
Comment by Irene Stanbrough | March 15, 2009
Hello Irene,
Sorry to hear about your cat …
In most cases this drug works well and enhances a hyperthyroid cat’s quality of life however as I said in the article side effects can occur.
Here is a link to more information on hyperthyroidism http://vetblog.co.uk/vetblog/hyperthyroidism-in-the-cat
Regards,
Scott
Comment by Scott | March 15, 2009
thankyou for your reply but our cat was loosing wieght and wouldnt eat had regular blood tests in last three weeks his red blood cells were getting less and vet didnt understand this its not normal he said so increased the doses to 5mg twice a day each time he went to vets was put on drip was better but once home 12 hours later bad again friday he couldnt stand up so off to vets again this blood test almost no red cells and vet said maybe hes alergic to pills so lets stop pills i came home he said come back in morning but he died in the night i was so cross as put in to google side effects of femizole? and came up with answer straight away to late for our beloved puss hope others will read site before it happens to theirs .
regards
Mrs Stanbrough
Comment by Irene Stanbrough | March 15, 2009
Hello again Irene,
I will be sure and leave your comments so other people can always read it.
Regards,
Scott
Comment by admin | March 15, 2009
Could you tell me if it is Law that the vet has to do a blood test at least once a year before giving a repeat for the drugs, also can they charge for each perscription. I now have 2 cats on Femimazole and it is becoming very expensive.
Comment by Gill | March 21, 2009
Hello Gill,
I assume from your e-mail address you are in the UK.
In direct answer to your question :
1. With prescription drugs such as Felimazole the vet is obliged to carry out regular checks before continuing with repeat prescriptions. These checks could be once every six months or once a year depending on the disease the animal is suffering from and the animal’s condition. The vet has some discretion as far as the length of the intervals go.
2. What form these checks should take is not laid down, it could be a very cursory clinical examination or it could include blood tests or other diagnostic tests. So it is not laid down by law that a blood test should take place, only that there should be an examination. This is largely left to the individual vet’s discretion.
3. With hyperthyroidism though a blood test would be a very accurate way to monitor your cat’s control with this disease.
Regards,
Scott Nimmo BVMS MRCVS
Comment by admin | March 21, 2009
I follow your blog for quite a long time and must tell that your articles are always valuable to readers.
Comment by Heartburn Home Remedy | April 15, 2009
Hello
My 15 (almost 16) beautiful tortishell suffered what my vet thinks was a stroke 10 days ago. Her balance went, her head was nodding and her eyes were flashing from side to side frantically. I called my vet immediately her advised me to keep her quiet for atleast 2 hrs. I waited (almost impossible) until in my heart I wasn’t happy to leave her any longer. again I contacted my vet and I was advised to take her in to my practice straight away. My vet advised that she had had a stroke and gave her a steroid injection. She was quiet for the rest of the day, but by night meowing frantically for food, which of course I gave into. The following couple of days my vet took blood and the results showed Hyperthyroidism. Mitzie is on 2.5mg of Felimazole twice daily. I’m unable to give her the tablet by putting it into her mouth as whilst doing this she became incrediabaly stressed and showed signs similiar to that of the stroke. She takes the tablet in food. I’m giving her a tiny portion with the tablet in to make sure she has taken it. Is this ok for her to have it in food? Also what signs should I look out for which could be of harm to Mitz. Is this likely to shorten Mitzie’s life and if treated could I expect to have my angel for atleast another couple of years?
Comment by Marie | May 26, 2009
Hello
I have a 1.5 years old male cat. He has almost all signs of hyperthyroidism, especially he become so aggressive, anxiety, sensitive, even I had to guarantee him in a separate room. He has ravenous appetite, he is always so thirsty, so hyper active, he has vomiting but he has mega esophagus problem too and because of that I’m not sure about his vomiting reason, he has poor coat. he has not weight loss but i should mention that he growths in 3 weeks rapidly and i can say his size become double from 3 weeks ago!
His blood test result for T4 is 4.4 mcg/dl (CLIA method) and TSH is 0.1 mlu/L (human lab)
I want to know, does he has hyperthyroid, my vet said No, but I’m not sure . if he has not then what is the reasons for his signs?what are T4 and TSH normal levels for his age?
Comment by mahtab | August 19, 2009
My cat also has thyroid problems and she does not take tablets….impossible …but with a pestle and mortar you can crush the tablet into fine powder and then mix it easily with a little food …it works a treat..my cat thinks she is having something very special to eat…do not give the cat to much food at once as she must eat all the mix…
Comment by Jean Briscoe | August 22, 2009
May just be a British thing but my very uncompliant cat (is there anthing else?!) has placildly licked a tab twice day for years off the end of my finger with it plopped on the top of a small blob of primula (Soft cheese in a tube). must admit have only used the original verson - not sure spring onion version would be so successful!
Comment by elizabeth H | September 3, 2009
One of my cats as recently been diagnosed with hyperthyroidism. She was initially taken to the vet for a dental check. She had bad breath and ?rotting teeth. The vet did a blood test with the resulting diagnosis hyperthyroidism. The cat is unable to have dental treatment until her thyroid blood results are improved. Is this correct? I am also very concerned as the tablets seem to have side effects. My cat has gone off her food, is vomiting, lethargic and appears to breathing rather rapidly. Is this something to worry about. Should I take her back to the vets immediately, or wait until another couple of weeks when she is due to have a blood test again.
I’m quite anxious about her. Is it possible that the vet has made a mistake.
Comment by Frances Hawkes | September 15, 2009
Frances do get your cat back to vet again ASAP
regards
Irene Stanbrough
Comment by Irene Stanbrough | September 19, 2009
My cat has recently been given felimazole by our vet, (cat aged 13+). But he never mentioned that one of the side effects was that he would lose his appetite, and I have been worrying that I could be losing my much treasured cat as he wasn’t eating enough. I phoned my vet and told him of my concerns and about what I had read on this web site and he assured me that you were very much in the right and that he was very remiss not to mention any of the side effects. Can I say thankyou very much for creating this website to offer people like myself information about different medicines
Comment by Tracey | October 13, 2009
Yes Tracey our Prince did not want to eat also(side effect) so was given high protein paste food in a tin which he did eat but not enough to make much difference to his weight good luck with getting your cat to eat if you can but as you know cats have a mind of their own.
Irene Stanbrough
Comment by Irene Stanbrough | October 13, 2009
Hi Tracey,
Glad you found the article of use …
Regards,
Scott
Comment by Scott | October 13, 2009
MY CAT 16YRS ON FELIMAZOLE ONE A DAY THEN VET SAID 2 A DAY AS BLOOD READIND HAD GONE UP WAS 900 THEN 325 THEN 750 ON 2 A DAY ITS GONE TO 9 BLOOD READING NOW UNDER ACTIVE AND THE KIDNEY BLOOD READING HAS GONE UP MY CAT SLEEPS ALL DAY NOW HAS PUT ON WEIGHT AND EATS OK … HELP SHOULD I STOP THE THYROID TABLETS AND WHAT ABOUT THE KIDNEY DAMAGE DONE RE THE PILLS THANKS A LOT cc.
Comment by cc | October 20, 2009
I think you should put into google search engine the wording “side effects of Femimazole” and read as much as you can and make your own decisions there is plenty to read thats why I asked for my first blog/comments to stay on this site so others could be aware and make their own choices about their beloved pet
Irene Stanbrough
Comment by Irene Stanbrough | October 20, 2009
Reading the comment by Jean Briscoe, August 22, 2009, I must warn her that my vet informed me that I shouldn’t crush up the felizamole tablets as they don’t work. I used to crush the tablet for my cat Yanni as hiding a tablet in his cat food didn’t work. I immediately stopped crushing them and I was lucky as Yanni would eat the tablet whole when I wrapped it in a little food before putting down his cat food. I’d have to vary the food I’d wrapped around the tablet but found that cheddar cheese, cooked liver, raw bacon, soft cheese, a small prawn - all these worked well. Occasionally he’d eat the food and out came the tablet from his mouth! But I’d try something else until he would swallow it whole often without even noticing it was in there.
I later read on the internet that crushing the tablets can cause the stomach acid to destroy the tablet.
The other bit of advice I can give is that if your cat is vomiting (as mine did) then a great product that worked for mine is from Pet.Alive.co.uk and it’s their capsules for digestive suport. It’s a herbal remedy that claimed to soothe gastritis, and only I wasn’t convinced I was desperately wanting to help my cat so gave it a try especially as the testimonials sounded promising. I would open up one capsule and sprinkle it on his food (half in the morning and half in the evening). After a prolonged period of intermittant vomitting I can say that after about 2 weeks on these tablets, Yanni never vomited again (only a couple of tiems which was more to do with eating grass). I put it down to the tablets and I am so grateful that in his last few months he didn’t suffer from vomiting. I would wholeheartedly recommended to for any pet that my be vomiting or off their food or could be showing signs of nausea.
I will try and answer any follow up questions if it will be of help to anyone.
Comment by Michelle Roman | November 18, 2009