Question of the Day

Persistent obesity, tail alopecia, and droopy, tragic facial expression are a classic signs of hypothyroidism in dogs. Other clinical signs include lethargy, exercise intolerance, and heat-seeking behaviors.

Hypothyroidism commonly causes dermatologic changes: dry skin, excessive shedding, hyperpigmentation, and poor hair regrowth. Areas of bilateral alopecia develop on the ventral and lateral trunk, caudal thighs, ventral neck, and dorsum of the nose. The tragic facial expression is due to accumulation of glycosaminoglycans in the dermis.

Hyperadrenocorticism (HAC) also causes dermatologic abnormalities: thin skin, truncal alopecia, comedones, scaling, pustules, and pyoderma, but these dogs lack the “tragic” facial expression. HAC is more common in toy dog breeds.

Images courtesy of Caroldermoid.