About Hyperthyroidism

Hyperthyroidism was not recognized as a problem in cats until 1979. It is now considered a common disease of cats. Both male and female cats are equally affected. It is thought that Siamese and Himalayan cats have a decreased risk of developing hyperthyroidism.

What is the thyroid gland and what does it do?

The thyroid gland is divided into two lobes, one on either side of the windpipe in your cat’s neck. The thyroid gland produces thyroid hormone (thyroxine). In normal  cats the gland cannot be felt.

The hormone produced by the thyroid gland is essential for the normal growth of the skeleton and brain in young animals.
It also has a wide variety of functions in adult animals:

• Involved in the control of metabolism
• Effects heart rate
• Helps control the breakdown of fatty tissues
• Involved in red blood cell production

What is hyperthyroidism?

Hyperthyroidism is when the thyroid gland makes and secretes very high levels of thyroid hormones. This is caused by abnormal changes or tumors in the gland. These abnormalities are usually benign and can be treated successfully. A small percentage of cases (1-3%) are more complicated to treat and generally have a poorer long-term prognosis

Causes of Hyperthyroidism

The cause of the abnormal changes in the thyroid tissue is not known.