Hyperthyroidism Is Common in Older Cats

Hyperthyroidism is common in older cats, but cats given canned food are two to five times more likely to develop hyperthyroidism than cats that eat dry food according to veterinarian Lee Pickett. Veera/Shutterstock

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.