Endocrine and Metabolic Diseases with Dermatologic Manifestations

Metabolic disease is high on the differential diagnosis list with crusting of frictional surfaces. Canine hypothyroidism is the most frequently diagnosed and misdiagnosed endocrinopathy. It is due to a deficiency in thyroid hormone, commonly due to immunemediated lymphocytic thyroiditis. Treatment of hypothyroidism involves the use of oral levothyroxine supplementation. Hyperthyroidism is one of the most common endocrinopathies affecting older cats and is usually due to either adenomatous hyperplasia of the thyroid or a single thyroid adenoma. Endogenous canine hypercortisolism is a relatively common endocrinopathy that usually affects older dogs. Feline hypercortisolism is a rare condition with infrequent dermatologic manifestations that are usually associated with iatrogenic rather than naturally occurring hypercortisolism. It is important to keep in mind that dermatohistopathologic findings are suggestive of an endocrine disease but are not pathognomonic. Skin changes due to abnormalities in sex hormones are rare and can be caused by abnormalities in the adrenal glands or gonadal organs.