The thyroid gland is a small gland located under the skin at the center of the neck. It is controlled by another small gland called the pituitary gland located at the base of the brain. This gland signals the thyroid to produce and release thyroid hormone. Thyroid hormone affects many parts of the body, from the hair coat to individual cell functioning.

A condition caused by too little circulating thyroid hormone in the blood stream. This is usually caused by the thyroid gland ceasing to function properly. Most of the time, there is no biological reason why the thyroid gland is not working properly.

The most common sign of hypothyroidism is a loss of hair, often on the tail, hindquarters or flank that is not the result of scratching. It may range from a very thin hair coat to complete baldness. Other signs include dry scaly skin, dry brittle hair, bleaching of the hair coat, possibly oily skin, increased pigmentation of the skin, thickening of the skin, increased susceptibility to skin and ear infections, and high blood cholesterol. It also may predispose the pet to a condition called “dry eye” due to thickened tears.

Advanced cases of hypothyroidism may cause lethargy and obesity, even on a limited diet. The pet may not want to exercise, may seek out warm places, and may have cold clammy skin. Breeding dogs may have a lack of libido and/or irregular estrus cycles.

Hypothyroidism is confirmed by blood tests.

Hypothyroidism is supplementation with thyroid medications. You should see an improvement in the overall condition of the pet in 2-4 weeks, but changes in hair coat take 1-6 months, depending on the rate of new hair growth for the particular pet.

The drug will need to be given for the rest of the dog’s life.

Blood tests to monitor the blood thyroid levels must be done on a regular basis to re-adjust the medication dosage as needed to maintain proper blood concentrations of the medication.