Coming Soon ×

Forgot your Password?


What Is Hyperthyroidism in Cats? catipedia-icon2.png

You've probably heard of thyroid conditions before, but what exactly is feline hyperthyroidism? For starters, it simply describes an overactive ("hyper") thyroid gland. Hyperthyroidism is also the most common glandular disorder in cats, usually found in "geriatric cats" ages 12 years or older. Fortunately, it's one of the most treatable. If you think your cat may have it, contact your veterinarian as the first and best way to get a qualified diagnosis. In the meantime, take a moment to learn about this condition and how it affects cats.

Are you the proud owner of a "geriatric cat"? Check out "Caring for an aging cat".


You can't talk about hyperthyroidism without talking about the thyroid gland: a large, two-lobed organ that surrounds a cat's windpipe. In cases of hyperthyroidism in cats, the gland swells and begins producing too much T3 and T4 - thyroid hormones that increase a cat's metabolism. In other words, these hormones signal your cat's body to convert nutrients (food and oxygen) into energy (calories) a lot faster than normal, like turning up the heat on a stove.

When these thyroid hormones "turn up the heat" on a cat's metabolism, a variety of symptoms may result. But keep in mind, most of the symptoms below aren't exclusive to hyperthyroidism; they could be symptoms of a different issue. Plus, remember that one cat with hyperthyroidism may experience just one or a few of these, while another cat may experience many more - and different - symptoms:

· Excessive thirst and urination

· Ravenous appetite

· Weight loss

· Vomiting

· Increased amount of stool

· Soft stools and/or diarrhea

· Panting

· Muscle weakness

· Restlessness or hyperactivity

· Unkempt, dull or excessively oily coat

· Excessive shedding

· Areas of hair loss due to excessive grooming

· Rapid nail growth


Diagnosing feline hyperthyroidism is a job for a veterinarian. He or she typically asks the cat owner about the more common symptoms from the list above and then performs a physical exam to feel whether the cat's thyroid gland is enlarged. If these preliminary steps point to hyperthyroidism, the veterinarian will usually conduct further tests to make a more conclusive diagnosis.

Prepping for a vet visit? There's a Catipedia article for that.

Hyperthyroidism in cats is highly treatable, with a positive outlook in most cases. Each treatment option has related challenges, such as cost, duration, and risk to the cat. If your veterinarian has diagnosed your cat with hyperthyroidism, ask about the recommended treatment options, as well as the pros and cons of each.


Hyperthyroidism in cats is a condition that deserves medical attention, but effective treatment options are available with a good track record for full recovery in most cases. If you're concerned your cat may have hyperthyroidism, schedule an appointment with your veterinarian.

Every cat deserves a long, happy, healthy life. Check out "Long Live Healthy Cats!" and learn 4 simple tips for cat health.


  • Plotnick A. Cat Fancy. "A Very Treatable Ailment." Sep 2014: 14-16.
  • Shojai A. The Purina Encyclopedia of Cat Care. 1998:191, 226-7.
  • Siegal M. The Cornell Book of Cats. 1989: 153, 244-5.



Below you'll find answers to some of the most frequently asked questions about our company, our products and caring for your cats. If you have a question that isn't addressed here, please feel free to contact us.

Q: How can I email or talk with the Purina Pet Care team?

A: If you would like to talk with us, please contact us here or call us at 1­-888­-228­-2469.

Our Hours of Operation:

  • Monday through Friday 7 a.m. to 7 p.m. CST
Q: How are Purina Cat Chow products different from other healthy pet foods?

A: Inside every bag of Purina Cat Chow you'll find a selective blend of protein, fat, and fiber. Everything we use in our premium cat food formulas has a place in your cat's healthy diet.

Q: How can I be sure of the quality of the Purina Cat Chow products?

A: Our top priority is the quality of the food that nourishes not only your pets, but the pets we share our lives with, too. So from source to bowl, the quality of our food is assured by taking the following steps:

Ingredient Sourcing

  • Purina ingredient sourcing and processing meet or exceed FDA, USDA or AAFCO standards for pet food. And every supplier of ingredients for Purina products must meet our stringent standards for ingredient specifications, product safety, sanitation and manufacturing practices.
  • Ingredient Testing
  • All of Purina's North American manufacturing facilities have on-site quality assurance laboratories and staff. And we're working to expand the use of technology to further screen ingredients for quality assurance.
Q: Where is your food manufactured?

A: 99% of all Purina-branded pet food products sold in the U.S. are made in Purina-owned U.S. manufacturing facilities. Purina's sophisticated tracking system ensures important measures of control: All raw ingredients are tracked from time of receipt at our plants, through their inclusion in finished products, and on to retailers.

Q: I am unable to find a particular product in my area. Can you help me locate it?

A: Yes, we can help. Although distribution of our Purina Cat Chow products is national, not all stores carry all sizes and varieties. Contact our Customer Service department via our Contact Us page or call us at 1­-888­-228­-2469.

Q: Do you offer coupons?

A: We recommend signing up to become a member of our MyPerks loyalty program to receive exclusive offers. We also offer coupons in local papers, through direct mailing programs and via emails to registered members. Make sure to watch for sales or promotions at your local retailer as well.

Q: Where can I find articles and information about my cat?

A: We believe there's always more to learn and to share and that discovery should be fun. It's one more way we're helping you and your cat share a better life together. Visit Catipedia for articles and information and... a little bit of fun.

Q: Help! My cat has a health issue and I’m not sure what to do.

A: We strongly recommend talking to your veterinarian for immediate answers to urgent situations. While is an excellent resource of information provided by cat care experts, your veterinarian can provide the best care for your individual cat.