Hypothyroidism in dogs is also commonly referred to as a Thyroid Hormone Deficiency. The illness occurs as a result of the low production and release of the T4 and T3 hormones in the dog’s thyroid gland. The thyroid gland is responsible for producing the hormones T3 (liothyronine) and T4 (levothyroxine), which are needed for the body to maintain a normal metabolism. When these hormones are missing, the dog will develop hypothyroidism, which can cause a variety of symptoms such as lethargy, weakness, unexplained weight gain, hair loss, excessive shedding, poor hair growth, mental dullness, skin infections, intolerance to cold, tilting of the head to one side and even seizures or infertility. The disease is believed to affect mainly medium to large breed dogs between the ages of 4 and 10 years. Neutered males and spayed females are believed to be at a higher risk for the disease. Talk with your veterinarian Hendersonville, NC for more information.