Hypothyroidism is deficiency of circulating levels of serum thyroid hormones. This causes a decrease in systemic metabolic rates. Hypothyroidism produces a number of symptoms that can lead to serious illness if left unattended. It is a very rare disease in cats.Classic signs of hypothyroidism are lethargy, hair loss, weight gain, mental dullness, fatigue, poor coat condition, exercise intolerance, recurrent skin infections, cold intolerance, infertility, hyperpigmentation and possible neurological deficits. Less commonly, cats can exhibit generalized