Feline Hyperthyroidism: What You Need to Know

 feline_hyperthyroidism

Hyperthyroidism is a common disease that typically affects middle-aged and older cats.  It is caused by an excess production of thyroid hormones, which are produced by the thyroid gland, located inside the cat’s neck. Thyroid hormones affect nearly all organs, which is why thyroid disease can sometimes cause secondary problems such as hypertension, heart and kidney disease.

Causes, Symptoms, and Diagnosis

For a comprehensive overview on what causes hyperthyroidism, what the symptoms are, and how it is diagnosed and treated, read Hyperthyroidism in Cats.

Treatment Options

Currently, there are three treatment options for hyperthyroidism in cats:

  1. Medication
  2. Surgery
  3. Radioactive Iodine (I131) treatment

Surviving Radiocat: A Personal Account

Amber was diagnosed with hyperthyroidism in 2005, and I chose the radioactive iodine treatment for her. For a personal account of our experience, please read Surviving Radiocat.

Can a new prescription diet cure hyperthyroidism?

Hill’s Pet Nutrition claims that its new diet, y/d Thyroid Health, an iodine deficient diet, can cure hyperthyroidism if fed exclusively. My gut feeling, when the diet first came out, was that it sounded too good to be true: simply change your cat’s food, and cure a potentially life-threatening disease? The ingredient list made me cringe. The dry version contains no animal protein; its protein is derived from corn gluten meal, soybean hulls and dried egg product. The canned product is only marginally better: it contains meat by-products, corn and rice. I’m not alone in my misgivings about the diet. Please read Can A New Prescription Food Really Cure Your Cat’s Hyperthyroidism for more information.

Are there alternative treatments for hyperthyroidism?

At a recent meeting of the American Association of Feline Practitioners, Dr. Steve Marsden, one of the chief educators of veterinarians worldwide in complementary veterinary medicine, with board certifications in Chinese herbology, acupuncture, and naturopathic medicine, shared his experience of treating hyperthyroidism with herbal medicine. These medicines may be useful with early cases, as well as during the stabilization phase, and they can easily be integrated into conventional treatment programs. While these herbal formulas are not as powerful as pharmaceutical drugs, they are generally safer and have fewer side effects. At a minimum, they may be able to lower the dose of conventional drugs. Read Herbal Medicine: A New Option for Treating Feline Hyperthyroidism for more information.

Before you make treatment decisions for your hyperthyroid cats, familiarize yourself with all treatment options, and don’t be afraid to ask your veterinarian to clarify anything you don’t understand.

Photo: Flickr Creative Commons

30 Comments on Feline Hyperthyroidism: What You Need to Know

  1. Sandy
    May 27, 2017 at 8:45 pm (4 months ago)

    My cat is 14. She had lost weight but this past week she stopped eating. Took her to the vet & she was diagnosed with hyperthyroidism. I have liquid merthimazole but she still won’t eat & hides from me. What can I do to get her to eat.

    Reply
  2. Viv
    December 4, 2016 at 5:32 am (10 months ago)

    I have a five year old cat with hyperthyrodism. In plain English can someone PLEASE let me know what I sbould be feeding him. Is fresh cooked chicken or lamb ok? Many thanks. Viv

    Reply
  3. lisa
    May 28, 2016 at 6:37 am (1 year ago)

    My 11 yr old cat was recently diagnosed with hyperthyroid, we initially brought her to the vet because she was urinating in very large diluted amounts on the bed, it was so diluted I didn’t even realize it was urine, I thought she had thrown up water, she has been drinking alot and is very vocal lately and has lost weight, her numbers were slightly high, so we started her on the low dose meds, do they start working right away and is the large amounts of urine normal? Please help, I’ve been reading as much as possible, but no one has said anything about urination! Thank you!

    Reply
    • Ingrid
      May 28, 2016 at 4:24 pm (1 year ago)

      Please contact your vet about the large amounts of urine, Lisa. That’s not normal, and may be an indicator of an additional problem.

      Reply
      • lisa
        May 28, 2016 at 4:41 pm (1 year ago)

        We just had her at the vet and all her blood work came back perfect, except for the slightly elevated thyroid, thank you so much for responding, any other advice is much appreciated

        Reply
  4. Diane
    August 10, 2015 at 1:23 pm (2 years ago)

    I have had a lot of experience with feline hyperthyroidism. I had one cat treated with methimazole for years and finally removal of one thyroid. She lived to be 16. Now I have a 13 year old tabby with hyperthyroidism who could not tolerate the meds. My cat received the I-131 treatment. I was more than thrilled with the results. Blood work shows after 12 weeks her levels went to normal. Her weight went up. No more pilling or watching her waste away. It was well worth the $900 we spent for the injection. Now that I have experienced all three ways to treat hyperthyroidism I would choose I-131 without hesitation.

    Reply
  5. Charmaine
    January 6, 2015 at 4:46 pm (3 years ago)

    My cat Pushkin is 17+ he was diagnosed with hyperthyroidism and was put on tabs Felimazole this made his neck and head swell so was changed to vidalta 15mg 1 daily, however the longer he had them the thinner he became, until he was just a bag of bones, the vets still insisted he needed them but I had my doubts he was dying right before my eyes although according to his bloods everything was ok. I took him off the meds and he has now gained nearly 1kilo in just 6days and is looking a lot better, he was down to just 3K. I have done a lot of research since and have changed his diet but am having trouble getting hold of something called thyroid support gold which is suppose to help to calm down the over active thyroid and restore a balance, the reports I have read are very positive but it seems that the only place to buy this is on line from America. does anyone know if there is a uk outlet for this, I know Amazon did sell it but they seem to have stopped and don’t know if they will be getting any more, any help with this would be appreciated

    Reply
    • Vicki
      February 9, 2015 at 3:53 am (3 years ago)

      Charmaine, I found the Thyroid Support Gold thru a site called Pet Well Being which ships International. It’s the one with 472 reviews. Also did you try eBay? I know main stream medicine says this is a case of too much iodine but I started giving my cat nascent iodine and he has settled down so I wonder. I am going to try the stuff from Amazon and this natural herb Carnitine you sprinkle over their food twice a day. Can reverse it in humans and cats and they are too low in it anyway. I just find it odd that here in the USA we are all way way too low in iodine and the Japanese who were much healthier took massive doses compared to our Recommended Dosage by our lovely government which wouldn’t keep a very small rat alive. Selenium is cheap and you and your pets really need that as is a great supplement for warding off cancers. Americans would rise up in horror if they actually had any idea how many of their dogs were dying from cancer. Young ages too.

      Reply
      • Joy Sarai
        March 3, 2016 at 11:46 am (2 years ago)

        I have a cat with hyper-t and have been trying left, right and center to get this formula – went on to ebay where it said it would ship to Israel – finally, we could start this on her – only to be told by the company via ebay – no, we don’t ship to Israel. But your auction says you do. They told me it was a mistake. So – we are basically without this formula. My cat is 17 and cannot take Methimazole nor do we have any of the options available in the States in terms of treatment. If anyone would like to help us please connect via boisenberryfiesta@yahoo.com

        Reply
        • BB
          April 14, 2016 at 9:56 am (1 year ago)

          Hi there, why don’t you get someone to purchase it for you and then post it to you?

          Reply
  6. Terri
    July 4, 2013 at 11:14 am (4 years ago)

    These two websites as well as yours, have been a big help to my cat Ringo. He is 14 and we used the medication route for him when he was diagnosed about 5 years ago. It was toxic for him. He recovered from that illness and we just did the best we could for him, but when I took him in this year, hip numbers were off the chart for thyroid levels. We tried the Y/D prescription diet (canned) for several months with great success. His levels went down to high normal (4) but then he got tired of the food and wouldn’t touch it. I did more research and discovered these two sites and so am making his food myself. He likes the variety I have come up with but the following sites helped guide me. He is due for another blood panel this month, so I will let you know how he is doing. From his behavior and weight gain, I believe it will be within normal limits.
    Here are the sites. One is actually a food list for humans needing to limit their iodine intake.

    http://www.2ndchance.info/lowIodine.htm

    http://www.cc.nih.gov/ccc/patient_education/pepubs/lo_ioi_list.pdf

    Reply
    • Ingrid
      July 4, 2013 at 2:57 pm (4 years ago)

      Would you let me know how his bloodwork looked, Terri? I’m intrigued with the possibility of a home-cooked low iodine diet. I’m not familiar with the veterinarian who recommends it on the site you linked to.

      Reply
      • Name*
        February 9, 2015 at 12:11 pm (3 years ago)

        Ringo is now 16. He refuses to eat the prescription Hills,Y/D diet for hyperthyroid cats. While he was eating it (for about 1/ 1/2 years, he blood work looked normal. Since he refuses the food, we have had to switch. I picked Wellness canned foods for him. He enjoys the variety and doesn’t seem any worse off for now. He also has arthritis and is on prednisone every other day for that. I guess at this point in his life, I am wanting quality of life rather than making him miserable with food he won’t eat or enjoy. I will take him in April to see how his levels are and get a general check up. Looking back, I wish we had done the permanent radiation treatment for him since he has lived for 6 years since the initial diagnosis.

        Reply
        • Terri
          August 19, 2015 at 12:25 pm (2 years ago)

          Our dear sweet Ringo passed away in April. He had gotten very thin and wasn’t grooming. He didn’t feel well and had no appetite. His thyroid condition was probably the cause, but since he was 16, we felt heroic efforts weren’t necessary. He passed peacefully at home just sleeping away his time. We loved him. Our new kitty who joined us before Ringo died is so much fun and full of life. His name is George. We still miss Ringo but know his time had come.

          Reply
          • Ingrid
            August 19, 2015 at 1:16 pm (2 years ago)

            I’m sorry about Ringo, Terri, but happy that George is there to help you heal.

  7. Michelle
    May 20, 2013 at 7:24 pm (4 years ago)

    I would make sure that there are no unknown health issues prior to the radiation treatment. A friend took her cat in for radiation only to have her die due to an previously undiagnosed heart condition. I know it’s a great treament, but like everything, there can be side effects.

    Reply
  8. Barb Call
    May 20, 2013 at 5:32 pm (4 years ago)

    Hi,

    I read your post a few months back regarding alternative treatments. My boy is 8 now and was diagnosed last year with hyper -t. Since only his free t4 was high and he is so young I decided to try the alternative route. I’m happy to report that we caught the disease early and it is in check. Here is what worked for us:

    1) Switch to commercial raw food (we use Primal or Natures’ variety – mostly Primal)
    2) Used Thyroid Support Gold from PetWellbeing – we were on 5 drops 2x per day but now
    reduced to 3 drops 2x per day
    3) Used 250 mg l-carnitine split in 2 doses each day (we have discontinued this since his
    values are normal)
    4) 30 mg of coq10 1x per day
    5) probiotics and digestive enzymes
    6) Ultra EFA from RX Vitamins for pets we use 1/8 tsp mixed in food 2x per day

    I am not a vet and have no medical training but I am happy to share that this worked for us – most likely because we caught the disease in an early stage.

    I have used I131 in the past with another older kitty – she was 18 and it made a big difference in her overall health although she developed cancer and we lost her about 6 months later.

    Best of luck to anyone who is struggling with this disease!

    Reply
    • Ingrid
      May 20, 2013 at 5:39 pm (4 years ago)

      Thank you for sharing your protocol, Barb. I’m so glad it’s working for your cat! I would encourage those of you who want to try this with your cats to work with a holistic veterinarian.

      Reply
  9. Sue Brandes
    May 20, 2013 at 1:19 pm (4 years ago)

    I also have a hyperthyroid kitty. My kitty gets the gel pen in the ears. My vet told me to wear gloves. And I wash my hands. We were on pills before. My kitty will be 21 this July and I am one of the lucky ones that he can tolerate meds. They only had surgery when he was first diagnosed and it was only a 50% chance. And pricey. Now they have so much more and also know so much more than when we found out. He just got high blood pressure this year so the vet is keeping a closer eye on him. He is doing pretty well.

    Reply
    • Ingrid
      May 20, 2013 at 5:07 pm (4 years ago)

      21! Wow, that’s wonderful, Sue!

      Reply
  10. Jenny | Floppycats.com
    May 20, 2013 at 11:11 am (4 years ago)

    As someone that was hyperthyroid for 8 years, I was faced with some of these options as well. I am pleased to hear that RAI works so well in cats. I am concerned about how vets handle the exposure to human pet owners and other pets in the household to these solutions.

    I recently found out that there is a Methimazole gel you can rub on their ears – however, the reader that told me this wasn’t aware of the dangers of her hands being exposed to that Methimazole gel. It appalled me that the vet didn’t convey to her that it could affect her!

    Reply
    • Ingrid
      May 20, 2013 at 11:23 am (4 years ago)

      Cats have to stay at the I131 facility for 3-10 days (regulated by the state), Jenny. The residual radiation these cats have is minimal, and you probably get worse exposure from standing near your microwave or watching tv! The transdermal methimazole should have come with instructions to use a glove when applying. In fact, this is true for most transdermal meds – it stands to reason that if they’re absorbed by the cat’s skin, they will also be absorbed by human skin.

      Reply
      • Maxwell, Faraday & Allie
        May 20, 2013 at 2:04 pm (4 years ago)

        Lisa here: I second what Ingrid said about I131. It only has a half-life of 8 days, so the levels quickly diminish. I like the “precision targeting” approach of I131 – especially after hearing the AAHA’s report in March on recent findings: new studies now indicate that sarcomas (cancer) are responsible for up to 25% of all hyperthyroidism in cats, as opposed to the 2-3% that had previously been thought.

        Also I like the stats on I131 – and surgery too: cat guardians who choose these options over Methimazole have longer survival rates.

        Reply
  11. The Preventive Vet
    May 20, 2013 at 11:05 am (4 years ago)

    Hi Ingrid, just saw this post on your Google+ feed. Nice work. It quickly caught my eye as I just recently contributed to an article about thyroid disease (in both cats and dogs) for The Oregonian newspaper – it ran this past weekend (http://www.oregonlive.com/pets/index.ssf/2013/05/pet_talk_thyroid_disease_a_man.html).

    Always love reading your stuff. Hope you had a great time at BlogPaws. I was sad to not have made it this year, but am hoping to do so again next year.

    Be well and have a great day!

    Jason

    Reply
    • Ingrid
      May 20, 2013 at 11:21 am (4 years ago)

      Thanks, Jason. BlogPaws was great – hope to see you next year!

      Reply
  12. Tom Randall
    May 20, 2013 at 10:15 am (4 years ago)

    As I think I wrote on another post related to this, our Jackie kitty was diagnosed with hyperthyroidism several years back. We tried the medical approach but her case was too severe so we decided to go with the radioactive iodine option. It was a complete success and she has been fine, we just took her in for a checkup last week and are having a thyroid panel done to be sure everything is still ok.

    So keep her in your thoughts or whatever you do, will let you all know how her results come out.

    Tom Mary Beth and the furries.

    Reply
    • Ingrid
      May 20, 2013 at 11:20 am (4 years ago)

      I’m glad to hear that the I131 treatment worked for Jackie. Fingers and paws crossed for a good checkup!

      Reply
  13. Tracey
    May 20, 2013 at 6:45 am (4 years ago)

    Just another reason to feed a raw, species-appropriate diet!

    Reply

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