Feline hyperthyroidism is a common condition in older cats caused by an overproduction of thyroid hormone by the thyroid glands. The overproduction is usually related to a benign enlargement of one or both thyroid lobes.

This disease most often affects cats over the age of 8 years however it can affect cats that are younger.

The most common signs of this disease is weight loss often with an increased appetite and increased activity.

For more information on this disease, please read Hyperthyroidism in Cats.