Q: Our senior cat is hyperthyroid. How common is hyperthyroidism, and what causes it?
A: Hyperthyroidism is caused by benign tumors in the two thyroid glands located in the cat’s neck. The tumors produce excessive thyroid hormone, which impacts all body systems.
Feline hyperthyroidism affects more than 10% of cats over age 10 and is now the most common endocrine disease of cats. It was first reported in 1979, and the prevalence is increasing.
Many factors play a role in the development of this disease:
— Age. Hyperthyroidism is common in older cats.
— Genetics. The Siamese, Himalayan, Persian and Burmese breeds are at low risk, so affected cats probably have a genetic predisposition….