Hyperthyroidism in Cats

Dr. Jason Gagné, DVM, DACVIM
By Dr. Jason Gagné, DVM, DACVIM
Updated: 6/3/20241-2 minutes
Hyperthyroidism in Cats hero

My cat is losing weight even though she eats well. What could be the problem?

Is your older cat high-strung? Does she lose weight but eat a lot? She may have an overactive thyroid. Older cats sometimes begin producing too much thyroid hormone. It’s a condition called feline hyperthyroidism. Veterinarians don’t know what causes it, but it speeds up the cat’s metabolism, causing a gradual weight loss and hyperactivity. In fact, hyperthyroid kitties are sometimes so high-strung, it can seem as if they’ve had a few too many cups of coffee! They will also drink and urinate a lot, and may lose hair, vomit or have a goiter or thyroid nodule.

If your cat displays any of these symptoms, contact your veterinarian. A blood test can detect the disease, and with appropriate treatment, a cat with hyperthyroidism can live a normal life.

By Dr. Andrea Looney, DVM


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