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Hyperthyroidism and Cats

By Michele C. Hollow of Pet News and Views

Did you know that peeing and pooping outside of the litter box can be signs of hyperthyroidism? It’s true. The thyroid controls our bodies’ metabolism—that goes for people and for cats. It also affects our behavior.

This is Earl Gray.

Earl Gray, my cat, recently started peeing and pooping outside of his litter box. He has been with us for 15 years. We found him as a cat and our vet guestimated that Earl was four years old when we found him. So at age 19, he started exhibiting this undesirable behavior. He also lost weight, even though he was eating a good amount of cat food.

From the moment he hobbled into our home (Earl was found with a badly broken leg), he had impeccable litter box manners. He never missed, and was careful to always cover up his pee and poop.

So after a few days Earl had a series of blood work done, and the test for hyperthyroidism came back positive.

The common signs for hyperthyroidism are:
• Weight loss
• Increased appetite
• Diarrhea and/or vomiting
• Increased thirst
• Poor skin and coat condition
• Hyperactivity

The one symptom that is often overlooked is behavior. My vet said that an over active thyroid will affect a cat’s behavior. That is why Earl was exhibiting these undesirable traits. I knew something was wrong because his behavior was out of the norm.

About Hyperthyroidism
The thyroid controls the body’s metabolism—in cats and in humans. It also controls our bodies temperature, blood pressure, heart rate, and gastrointestinal function. If your cat has hyperthyroidism, his thyroid gland will be enlarged. It will also produce large amounts of thyroid hormone—making it overactive.

Hyperthyroidism is common in older cats. Many cats over the age of 10 are diagnosed with this disease. The good news is that it is treatable. Our vet recommended Methimazole, a pill you can get at your pharmacy with a prescription from your vet. Earl had to take half a pill in the morning and the other half at night.

I mixed it into his food, and most of the time he ate it. The pill is extremely tiny—like the size of a small birthmark.

Pilling a cat can be tough. I’ve had to give meds to my other cats, and almost always the bowl was licked clean with a tiny pill at the bottom.

Earl took his pill. I purchased a small amount of American cheese and would wrap a tiny bit around the pill. He usually ate it that way. I know cheese is not the best food for a cat, but it worked. I hate American cheese, but it is quite malleable and hid the pill completely.

A month later, I took Earl back to the vet and he got a good report. He even gained a half pound. My veterinarian wanted me to forgo the pill and change Earl’s diet to the new Hill’s Prescription Diet y/d Feline Thyroid Health brand pet food.

I had just toured the Hill’s plant and learned about this new formula. Hill’s Prescription Diet y/d Feline Thyroid Health brand limits the levels of dietary iodine to reduce thyroid hormone production and helps restore thyroid heath. It also supports kidney function. The controlled mineral levels in the food help maintain a healthy bladder, and the high levels of omega-3 and -6 fatty acids promotes healthy skin and coat. Plus, it promotes heart health with essential nutrients like taurine and carnitine.

If you suspect your cat has hyperthyroidism, take him to your vet for a blood test. You can try this new diet, which is only available at veterinarians’ offices. The food comes in cans and dry. I never fed Earl dry food, but honestly, he doesn’t like the cans. He eats the dry food.

We go back to the vet in another week. So far, he is doing well. He has been on the diet for three weeks now. I’ve stopped giving him meds, and he is using his litter box. I was so excited because he started covering his poop, which most cats do, and he has always done—except while he was sick.

So if your cat starts exhibiting unusual behaviors, take him to the vet. If you give your cat Hill’s y/d, I would love to hear from you. I know it’s new, but I’m curious to learn how it is working for your cat.

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43 comments to Hyperthyroidism and Cats

  • This is a great resource for our friends with thyroid disease. I am so happy that Earl is feeling better and for you that he is once again covering his….tracks. ;)

  • Marcus

    Thanks for this information. A lot of people don’t know that hyperthyroidism affects behavior. We know about the other symptoms that you mentioned in your post. Thanks!

  • Anna

    Thank you for this blog post. My cat also has hyperthyroidism. I am going to talk to my vet about getting off the meds and trying this diet.

  • Mary

    I didn’t know about behaviors. We have a 12 year old cat and she is fine right now. It’s good to know. I will bookmark this article. Thanks!

  • Patrick M. Donovn

    Thank you for this article. We have 2 cats with hyperthyroidism and this additional information is very helpful

  • Fulvia

    Thank you, Michele! Very interesting article, very helpful!

  • Sandra

    Good to know. As others have stated, most of us know about weight loss and hyperthyroidism and the other symptoms you mentioned. I have not heard about behaviors. Thanks! It’s especially good to know because I live with cats.

  • Danni

    Thanks Michele, I have two cats, and one is almost 16. I will watch out for this.

  • Carol Hupp

    thanks so much Michele for this info, yes I have 7 rescued kitty babies and this is good to know if any start exhibiting that kind of behavior!

  • Louis

    Like Daniela said, some people think the cat is being mean, when it is not well. good post.

  • Thanks for this post, Michele! Sometimes people tend to think their cats are being mean when they pee or poop outside the box. It’s never the case. And the first thing people should do is take the cat to the vet asap to rule out any diseases. :-)

  • Betsy Conner

    My cat just started on Hill’s y/d Prescription diet too, and it seems to be working.

  • Thanks Daniela, I was so baffled by Earl’s behavior. This was so out of the ordinary for him. You are right: we need to take our pets to the vet if something seems wrong.–Michele

  • katsrus

    Thanks for this post. My cat Squeaky has had this for about 10 years. The vet said he is doing well and looks much younger than his 15yrs this last visit. It’s always good to watch for behaviors that are not normal for you cat.

  • Fern

    Great article Michele. Thanks. Like your other readers, I have older cats.

  • Troy

    Glad to hear that Earl is doing well. He’s such a great cat. And another good article Michele. Thanks!

  • Mercedes

    Perfect timing Michele! We are taking our cats in for annual checkups and the 16 year old is losing weight. I am going to talk to our vet about this. It’s good to know about an alternative to meds.

  • Robert

    I too am going to ask my vet about y/d since I have an older cat who is losing weight. I just scheduled a vet appointment. Thanks!

  • Erin

    Glad to hear about this product. I have senior cats, and when it comes time to adopt, I always choose seniors. Thanks Michele!

  • Henriette Matthijssen

    Thanks for the info. Michele, it is always good to know when a pet is not doing well. Glad to hear your Earl is ding fine now.

  • Hayden

    Are cat, Simon, is doing well with Hill’s Prescription diet y/d. He had to get used to it, and I’m pleased that it is vet recommended. Thanks for this post.

  • Amanda

    Our vet has recommended Hill’s Presciption diet for our cat too. So we are just trying y/d. Thanks for writing about this.

  • Chelsea

    Wonderful post. Glad to hear Earl is doing better.

  • Jack

    I hope you write another post on Earl. Give us an update. I have two senior cats, and will talk to my vet about Hill’s y/d. One cat is losing weight.

  • Thanks Michele I am so glad that Earl is doing better and that you found out the cause of this, I don’t have any cats I have four dogs, So good to know for people that have cats.

  • VL Smith

    Be sure if U put your cat on the y/d that they eat the required schedule. If they don’t, take them to your vet asap & have bloodwork done. My cat didn’t eat the required food starting the 5th day & now I’m having trouble getting him to eat @ all.

  • Isabelle

    My cat, Lady, eats y/d. We just tried it about a month ago. She is 16 years old and was diagnosed with hyperthyroidism. It took her a while to eat the food, but I want her to get better. She won’t touch the cans either. The dry food is tolerable. I sometimes mix gravy in with it.

  • Shane

    Glad to hear Earl is doing well. We just found out our cat, Herman, has hyperthyroidism. I am going to talk to our vet to see if we can try y/d. Thanks Michele for this helpful post.

  • Janet V

    My cat Sisko was recently diagnosed with hyperthyroidism and put on methimazole. He was doing OK for a while, but has since started losing weight again and now is having problems with the litter box. We’re going to take him back to the vet and hopefully upping the meds will help. I will definitely ask about the Hill’s. I read about it and was wondering where to get it. Now I know. Thanks!

  • Travisogan

    Good to know Michele. I have three senior cats.

  • Hi Janet, Good luck with Sisko. I hope he gets better. –Michele

  • Hi VL, Earl wouldn’t eat the canned food. He is getting used to the dry. I have mixed some gravy in with it. I know that is not what I should be doing, but he is eating it that way. He goes back to the vet in a month. I hope your cat is doing better. Michele

  • Hi Jack, I will give an update on Earl’s progress. Thanks, and I hope your cat is okay.–Michele

  • I’m so glad Earl Gray is feeling better. My eldest cat goes for blood work twice a year. If any thyroid issues develop I’d be very interested in trying Hill’s y/d food rather than a pill. One of my boys is prone to urinary crystals but has done perfectly well, for several years, merely feeding him Hill’s c/d.
    Both of these Hill’s foods are the prescription diets.

  • I’d like to add that I would never be able to give my eldest a pill even once. She won’t allow it and becomes Zelda Scissor Hands!

  • Neil

    Glad to hear that Earl is doing well. I will look for a progress report since this is new to him. I have older cats–ages 12, 13, and 15. They are all in great shape. I do feed them Science Diet.

  • LittleStar

    What Great Information. Have had to face this many times with my rescues.
    HEY, I could use the 150 lbs of litter here at my Hospice

  • Marcie

    I’m Bookmarking your post as http://petnewsandviews.net/2011/11/hyperthyroidism-and-cats/ at Digg.com. Great post.

  • Kim O

    Thanks for the great info Michele!! Happy to hear that Earl’s feeling better!! I hope my meows get to live that long!!

  • Rick

    Very useful article. As you mentioned, it’s not really reported that behaviors are affected by hyperthryoidism. Thanks.

  • I hope so too Kim!–Best, Michele

  • Love the post! I bookmarked it http://petnewsandviews.net/2011/11/hyperthyroidism-and-cats/ at Digg.com so all my buddies can check it out and come on over to your site. Thanks Michele!