Cat Losing Weight

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Health and Nutrition

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

The following article is taken from the "Purina® Animal Instincts” Podcast Series. Learn more at

Is your older cat high-strung? Does she lose weight but eat like a pig? 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 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 the symptoms, contact your veterinarian. A blood test can detect the disease, and with appropriate treatment, a cat with hyperthyroidism can live a normal life.

– Dr. Andrea Looney, DVM