Feline Hyperthyroidism

In normal cats, the thyroid glands in the neck produce the right amount of thyroid hormones. These hormones regulate your cat’s metabolism, which influences all body systems. Hyperthyroidism is a common disease in older cats. It is a multisystem disorder caused by high levels of thyroid hormones, usually produced from a benign change in one or both thyroid glands. It is diagnosed with a simple blood test, T4. Clinical signs of hyperthyroidism in cats include weight loss, increased appetite, increased thirst, increased urination, vomiting, diarrhea, and unkempt coat. The disease can cause high blood pressure, heart disease, blindness, and sudden death.

Thankfully, hyperthyroidism in cats is treatable. There are three options for treatment:

1. Oral medication – Usually pills given twice a day, probably the least expensive treatment option. However, up to 20% of cats will have some side effects with the drug. Alternately, transdermal medication may be used.Also, the medication must be given for the rest of your cat’s life.

2. Surgery – Surgical removal of the affected thyroid gland or glands can be done. As with any surgery, there are risks involved with the surgery and with the anesthesia. Some cats with hyperthyroidism are especially poor anesthesia risks, due to high blood pressure, heart disease, kidney disease, or other metabolic diseases.

3. Radioactive iodine treatment – A very effective way to treat hyperthyroidism in cats. It is given as an injection, gradually destroying all abnormal thyroid cells without endangering other organs. Radioiodine treatment is expensive, and requires a week of hospitalization in a specialized referral veterinary center.

If you have any questions about feline hyperthyroidism, or any other concerns about your older pets’ health, please do not hesitate to contact us.