Diagnosing Dog Thyroid Problems

The dog thyroid is a small gland in the throat that produces thyroid hormones. These hormones help regulate your dog's metabolism. When the thyroid gland is damaged or malfunctions, your dog can suffer from thyroid problems.

The Role of the Thyroid

Your dog's thyroid gland is located just under the skin in the middle of his throat. It works in conjunction with the pituitary gland to produce a thyroid hormone called thyroxin. The thyroid is an important part of your dog's endocrine or hormonal system. The hormone it produces affects nearly all of your dog's body systems. If a dog's thyroid gland fails to produce just the right amount of thyroxin, widely varied symptoms can result.

Hypothyroidism in Dogs

Hypothyroidism is a disease that occurs when your dog's thryoid gland fails to produce sufficient quantities of the thyroid hormone. Any dysfunction in the pituitary, thyroid or hypothalamus (three important glands in the endocrine system) can lead to hypothyroidism. Most cases of canine hypothyroidism are the result of damage to the thyroid gland itself.

Vets don't really know what causes hypothyroidism in dogs, but they suspect that it may largely be the result of an autoimmune disorder that damages the healthy cells of the thyroid gland. The disorder usually affects dogs between the ages of 4 and 10, and is more common in mid-sized and larger breeds. Some breeds are more prone than others to hypothyroidism. They include:

  • Golden Retriever
  • Irish Setter
  • Miniature Schnauzer

Because hypothryoidism is a disease that affects the entire metabolism, symptoms can be vague and varied. They include:

* Lethargy * Hair loss * Weight gain * Dry coat * Excessive shedding * Changes in skin color * Intolerance to cold * Lowered heart rate * High cholesterol * Anemia

Hypothryoidism is diagnosed with the help of a blood test that detects levels of thyroxin. If levels are too low, the diagnosis of hypothyroidism is made. Hypothyroidism in dogs is easy to treat with a daily oral medication, though it may take some time to perfect the dosage, and the dog will need to continue taking the medication for the rest of his life.

Hyperthyroidism in Dogs

Hyperthyroidism is a disorder in which the thyroid gland becomes overactive and produces too much thyroxin. Hyperthryroidism occurs much less frequently in dogs than hypothyroidism. It usually occurs as the result of thyroid cancer.

Hyperthyroidism causes your dog's body systems to work overtime, and can have serious consequences. Hyperthryoidism increases your dog's heart rate, and, if not treated, can lead to a condition called myocardial hypertrophy, in which the heart increases in size.

Symptoms of hyperthryoidism in dogs include:

  • Increased appetite
  • Weight loss
  • Vomiting
  • Diarrhea
  • Excessive thirst
  • Hyperactivity
  • Nervousness
  • Increased heart rate
  • Increased respiratory rate
  • Dull coat

There are a few different ways to treat hyperthyroidism in dogs. Oral medication can help regulate the production of thryoid hormones in many dogs. Surgery can be performed to remove part, or all, of the thyroid gland (in which case, the patient would need to receive synthetic thyroxin as if he suffered from hypothyroidism). A surgical procedure known as radioiodine treatment uses radioactive iodine to kill overactive thyroid cells, but this procedure isn't suitable for all dogs.