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.
How Hypothyroidism Affects 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 signs of unkempt appearance, matting of hair, lethargy and obesity.
The lobes of the thyroid gland are located along the underside of the neck, just under the lower jaw, and play a key role in controlling the rate of metabolism. In normal operation, the thyroid gland produces and secretes hormones that circulate through the vascular system and encourage cells to process the building blocks for energy metabolism. When thyroid hormones are decreased, the animal's metabolism slows down and causes negative effects on many of the animal's body processes.
Causes of Hypothyroidism in Cats
Most cases of hypothyroidism in cats are caused by damage to the thyroid gland after surgery (bilateral thyroidectomy) or radioactive iodine therapy. It is very uncommon for cats to develop hypothyroidism otherwise. Congenital hypothyroidism is very rare in both dogs and cats.
Preventing Hypothyroidism in Cats
There is no way to actually "prevent" hypothyroidism in cats. Proper treatment can prevent recurrence of clinical signs.
This is an uncommon disorder in cats. The long-term prognosis is good to excellent for return to full function if a cat develops this disease and is treated appropriately.