Dr. W. Jean Dodds is a world renown vaccine research scientist and founder of Hemopet, a nonprofit animal blood bank in Southern California. Her latest book is "The Canine Thyroid Epidemic: Answers You Need to Know for Your Dog," written with Diana R. Laverdure (Dogwise Publishing, 175pp., $19.95). She answers this week's questions about canine...

hemopet2.jpgDr. W. Jean Dodds is a world renown vaccine research scientist and founder of Hemopet, a nonprofit animal blood bank in Southern California.
Her latest book is
“The Canine Thyroid Epidemic: Answers You Need to Know for Your Dog,” written with Diana R. Laverdure (Dogwise Publishing, 175pp., $19.95). She answers this week’s questions about canine thyroid disease.

Question: What role does thyroid play in a dog’s health and function?

Answer: In all mammals, the major “master glands” that basically control all body functions are the pituitary gland in the head and thyroid gland in the neck.

The pituitary gland “tells’ the thyroid gland what to do, based on the blood levels of free thyroid hormones that circulate through it. When these levels are low, the pituitary gland releases a hormone called thyroid stimulating hormone (TSH), which causes the thyroid gland to increase its output of thyroid hormones.

By contrast, when the circulating levels of thyroid hormones are high, the pituitary gland releases less TSH to reduce further output of thyroid hormones.

Question: Why is it so important?

Answer: Because thyroid hormones, released from thyroid glands, control all the organ and cellular functions of the body.

Question: You say there is an epidemic in canine thyroid disease. Please explain how you reached this conclusion.

Answer: Decades of line breeding and inbreeding within purebred dog breeds — and even the crossbreeds and mixed breeds — were designed to “fix” the physical appearance, behavioral and performance traits of particular breed types to standardize the breeds and make them more alike genetically. However, this also placed them at an increased risk of being affected by undesirable health or behavioral conditions.

When we add the increasing effect of pollution of our environment, depletion of the ozone layer in the atmosphere, accumulation of toxic wastes and appearance of more infectious agents, parasites and chemicals to this genetically similar and thus susceptible population of dogs (or other animal species and humans), the increase in autoimmune conditions, including endocrine disorders, becomes inevitable.

Thyroid disease is one of the most vulnerable of these conditions.

Question: Why is the epidemic such a serious issue?

Answer: Because thyroid dysfunction directly affects the health and longevity of the body.