Q. How is low thyroid related to Cushing's disease?
DR. CHRISTIE LONG, D.V.M., C.V.A.
A. They're not really related, but if your dog has Cushing's disease and also has a low thyroid reading I would suspect she in fact DOES NOT also have hypothyroidism but instead has something called euthyroid sick syndrome. Because the thyroid controls metabolism, we'll often see the body downregulate the production of thyroid hormone when there's disease elsewhere. Typically once the dog is well or the primary disease is controlled, thyroid numbers return to normal.