Thyroid glands are small glands that are present on each side of the neck and secrete thyroid hormone which plays an important role in the regulation of the body’s metabolism. When the thyroid hormone is secreted in excess, this increases the body’s metabolic rate and the condition is known as hyperthyroidism. Hypothyroidism is when there is a deficiency of the thyroid hormone in the body and the metabolic rate of the body becomes slow. Hypothyroidism is more prevalent in middle-aged dogs while hyperthyroidism is rare and often associated with thyroid cancer. Certain breeds e.g.: Golden Retrievers, Doberman Pinschers are at higher risk to develop the disease. Dogs having hyperthyroidism show symptoms like decreased metabolic rate, low energy level, weight gain, and conditions that involve skin like thinning f hair coat, dry skin, and skin infection. To treat this condition, lifelong oral supplementation of thyroid hormone is prescribed. Dogs on oral supplementation can live an active and healthy life.