Is your dog lethargic and overweight, or does your cat eat everything in sight but continues to lose weight? They may suffer from disease of the thyroid gland. The thyroid gland is located in the neck and is responsible for controlling the body’s metabolism. Dogs often suffer from hypothyroidism, a lack of thyroid hormone production, leading to a slowing of their metabolism. Cats often suffer from hyperthyroidism, an excessive production of thyroid hormone, leading to a speeding up of their metabolism.
Hypothyroid dogs usually act lethargic, gain weight, have dry, thin hair coats, may shed excessively and often don’t like the cold weather. Certain breeds are more commonly affected such as Labrador Retrievers, Doberman Pinschers, and Rottweilers, although any dog may suffer from this illness. Dogs suspected of being hypothroid can be diagnosed by a thorough physical examination and blood tests. Special thyroid hormone testing is often necessary to aid in the diagnosis, however many dogs may have results that make it difficult to firmly establish a diagnosis of hypothyroidism. In these cases, your veterinarian may suggest a therapeutic trial (giving medication to see if it helps) of thyroid hormone supplementation or further testing.
Hypothyroidism is treatable but not curable. Dogs are given oral thyroid hormone replacement medication. This treatment is usually given for the remainder of the dog’s life. Most dogs will need to have their thyroid hormone levels checked a few times each year by their veterinarian. The good news is that during treatment most of the problems such as lethargy, weight gain and hair loss improve, and many dogs lead normal, healthy lives.
Cats usually have the opposite thyroid problem of their canine friends. Their thyroid gland may develop a benign tumor that produces too much thyroid hormone. This speeds up their metabolism, leading to excessive appetite with weight loss, increased thirst and urination, vomiting and/or diarrhea, and a poor hair coat. Usually only geriatric cats, those greater than eight years old, are affected with hyperthyroidism. Diagnosis is made by a through physical examination and often a single set of blood tests, checking overall body health and a thyroid hormone called T4. Unfortunately, hyperthyroidism can affect many of the cat’s vital organs such as the heart and liver, and may cause significant high blood pressure.
The good news for hyperthyroid cats is that many of them can be cured. A single injectin of radioactive iodine, given at a special veterinary facility licensed to handle radiation, is safe and often all that is required to cure Kitty. Two other treatment options include surgery to remove the affected thyroid gland (this often leads to a permanent cure) or the administration of oral medications that stop the production of excessive thyroid hormone. The disadvantage of the oral medications is that while they control the disease, they don’t cure it. These medications must therefore be given for the life of the cat and may have serious side effects. The best treatment plan should be discussed with your veterinarian.
So, if Bowser suddenly acts lethargic and is gaining weight, or Kitty is always eating but losing weight, schedule an examination with your veterinarian to determine whether they are suffering from disease of their thyroid gland
Courtesy of Jay H. Margolis, D.V.M., M.S. Centreville Square and Chantilly Animal Hospitals 703-222-9682 703-802-8387