Pathogenesis, clinical features and diagnosis of feline hyperthyroidism

Hyperthyroidism is the most common endocrinopathy occurring in cats. Breed or sexual predilection has not been confirmed, but hyperthyroidism is rare in Siamese and Himalayan Cats. This kind of thyroid dysfunction usually occurs in cats over 6 years old. Some clinical features result from hypermetabolism and the most common are: hyperactivity and hyperexcitation, weight loss, tachycardia, polyphagia, polyuria, polydipsia, unkempt hair coat with excessive shedding and matting of hair. Diagnosis should be based on case history, physical examination, laboratory tests and additional diagnostic tests, e.g. thyroid scanning.