Hypothyroidism is one of the most common hormonal disorders in dogs, causing weight gain, lethargy, and skin problems that respond well to treatment.
Dogs with untreated hypothyroidism experience fatigue, obesity, cold sensitivity, skin thickening, and in severe cases, myxedema coma. These dogs are often misidentified as lazy when they are actually metabolically impaired. Once treatment begins, dogs typically transform rapidly, becoming energetic and bright-eyed within weeks.