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Hyperthyroidism in Cats: A Reason for the Munchies

June 26th, 2017 by Cherished Companions Animal Clinic

Sophie has been drinking a lot of water lately -- one symptom of hyperthyroidism in cats.

Your cat has been acting strange lately…

Eating a lot. Drinking a lot. Losing weight. Crying more than usual. And making a lot of trips to the litter box.

It’s possible your cat may have hyperthyroidism — also known as an overactive thyroid and as cat thyroid disease.

Hyperthyroidism in cats isn’t as common as cat diabetes or renal disease.

Nonetheless, it’s the most common gland issue for cats.

And it’s something you want to catch and treat early!

What is hyperthyroidism in cats?

Hyperthyroidism means your cat’s thyroid is producing too many hormones.

This is likely due to a tumor on the thyroid gland, which is causing over-activity. (Most of these tumors are benign.)

Your cat’s metabolism has gone into overdrive. Your kitty can’t eat enough to keep up.

The earlier you catch hyperthyroidism in your cat, the better.

Hyperthyroidism can lead to a variety of problems in your cat’s body — from blood pressure issues, to heart disease.

And we know you want your cat to live a long and full life!

Our veterinarians often see feline hyperthyroidism in older cats, such as in this cat, Marmalade.

What are the symptoms of hyperthyroidism in cats?

Our Castle Rock veterinarians will look for clinical symptoms such as:

  • Weight loss
  • Extreme hunger (your cat may eat so much that he vomits)
  • Increased thirst and urination

These symptoms tend to come on very quickly.

We also may ask you about symptoms such as:

  • Excessive crying
  • Changes in your cat’s meow (because the thyroid is near your cat’s larynx, you may notice that his meow sounds different)
  • Panting
  • Hyperactivity
  • Coat changes
  • Vomiting

It’s worth noting that there are other health problems in cats that have similar symptoms.

So if you notice these symptoms in your cat, it’s important to come in and visit our veterinarians.

Noticing some strange cat behavior?

Let’s catch issues early! If you live in Castle Rock or the Denver area, call us at 303-688-3757 or:

Book a visit here 

How do I know whether my cat has hyperthyroidism?

It requires a special blood test to diagnose it.

Are certain cats more vulnerable than others?

Typically, our Castle Rock vets see hyperthyroidism in middle-age and senior cats — cats that are 10 years or older.

Tigger, the cat, sits on a wall. His long hair masks his recent weight loss.

How do you treat cats with hyperthyroidism?

Treatment options vary, and we’ll tailor a solution to your cat.

We may recommend visiting a cat specialist, so your cat can get surgery or undergo radiated iodine treatments (similar to how human thyroid cancer is treated).

There also are oral medications, topical medications and diet treatments.

Initially, you can expect several visits to the vet. We’ll check your cat’s thyroid and assess the dosage of medications.

We want to make sure that no underlying issues have arisen, such as kidney or renal issues.

(To learn more, check out this article on treating feline hyperthyroidism from Cornell University College of Veterinary Medicine.)

What’s the recovery for cats with hyperthyroidism?

Typically, your kitty can get back to normal if he or she stays on daily medication.

It depends on your cat, so let’s chat about it at your next visit.


Cherished Companions Animal Clinic is a veterinary clinic in Castle Rock, Colorado. Specializing in the care of cats and dogs, our goal is to help you and your pet feel more comfortable, keeping your stress to a minimum.

This article is intended to provide general guidance on hyperthyroidism in cats. If you have specific questions or concerns, please contact your local veterinarian. (If you live in or around Castle Rock, we welcome your call.)

© 2017, Cherished Companions Animal Clinic

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