One More "Tail"

Thyroid disease in humans is the primary focus of this book. However, some readers, especially pet owners, might find it interesting that animals, particularly dogs and cats, develop thyroid disease, too. Dogs are more likely to develop hypothyroidism, and cats are more prone to hyperthyroidism (see Thyroid Newsmakers: "One Last 'Tail' ").

If a dog becomes overweight, sedentary, and loses hair, a veterinarian may suspect that the dog is hypo­thyroid. The veterinarian may measure the dog's T4, T3, free T4, and TSH to confirm the diagnosis. When hypothyroidism is confirmed, dogs take the same medication as humans-Ievothyroxine.

According to Dr. Brian Poteet, a veterinary radiologist, "Hypo­thyroidism is a problem, but not a huge problem [in dogs]. The real problem is that it is over-diagnosed." When a dog gets sick from non­thyroidal illness, the results of the dog's thyroid function tests can be misleadingly low. Therefore, a veterinarian may assume that the dog's thyroid gland is causing the dog's ill­ness when, in fact, something else is wrong. Dr. Poteet says, "Many dogs are supplemented if they need it or not. It won't do that much harm, but the real problem is that a veterinarian can miss what is really wrong with the dog.

As fate would have it, I have had three Doberman Pinschers, and all of them have been hypo­thyroid. Curiously, dogs require a much larger dose of levothyroxine than humans. At one point, I my sixty-pound Doberman took 900 micrograms of levothyroxine daily, approximately fifteen times the dosage needed to treat a sixty­pound human. Somehow, it seems only appropriate that a thyroidologist would have hypo­thyroid dogs!