Part I: What's So Big About the Little Thyroid?

By Jan Cooper

This small gland is a hormone producer that affects many parts of the body. When certain diseases or ailments are suspected in a dog, testing for a thyrod imbalance can often lead to a more accurate diagnosis and better treatment. The little thyroid is more often than not one of the guilty culprits. Edward Baker, VMD, refers to the thyroid as "the body's chief engineer." This important little gland consists of two oval bodies located in either side of the neck. There are also tiny parts of thyroid tissue in other areas of the chest and even around the heart. There are two (2) forms of thyroid hormone secreted by the thyroid gland; T3 (triiodothyronine) and T4 (thyroxine). T3 is usable thyroid hormone while T4 must first pass through the liver and other tissues before it can become T3, the usable thyroid. Here is where it begins to get a little complicated, but I'll do the best I can to help simplify it. The thyroid gland itself is regulated by two different hormones, TRH and TSH. Now, if T4 gets too low, (remember it's not usable yet when it starts traveling around the body) the brain tells the TRH, "Hey, wake up, go get TSH and tell him to get to work!" Now TRH knows that TSH 'hangs out' at the nearby Pituitary gland, and so heads straight there to find him. Well, as soon as TSH hears about the thyroid shortage he races to the thyroid gland and stimulates it to get busy and produce more thyroid hormone. Hence TSH stand for THYROID STIMULATING HORMONE while TRH, being the first one to be released into active duty, is the THYROID RELEASING HORMONE. As a consequence of all of this, Hypothyroidism (the shortage of usable thyroid in the body) is usually the condition seen when a thyroid imbalance is suspected. Hypothyroidism is becoming all too common in our breed and all of our dogs should be tested. Why do skin problems seem to go hand in hand with thyroid imbalance? In order for our dogs to have healthy skin and coats, the cells that make up the body must be healthy and multiply. It is not fully understood, but thyroid hormone is essential in regulating the metabolism of each individual cell. Whenever the cells cannot function efficiently, one of the visible results is the skin will loose it's elasticity, and can ultimately result in dry, crusty, scaly skin. The end result can be a dog with a very sparse coat and a dull, almost hardened gray skin that will have a obnoxious odor. A dog left untreated will be miserable with uncontrollable itching all over and will further damage itself by chewing to the point of producing raw and oozing sores, a setting ideal for bacterial infections. It is found to be a fact that hypothyroidism is definitely associated with reduce resistance and a greater susceptibility to bacterial infections. So if your dog develops any type of skin ailment or a wound that does not seem to respond readily to treatment, you might want to check for a thyroid deficiency.