There are actually several treatments available for Feline Hyperthyroidism.

Drugs can be given that block thyroid hormone utilization. These drugs have to be given at least twice daily and can lead to stomach upsets in many cats; especially when the initial dose needs to be increased over time. Additionally, side effects including scratching or rubbing the face, decreased white blood cells, elevations in liver enzymes and decrease in platelets causing increased bleeding problems may occur. It must be remembered that these drugs do nothing to deal with the enlargement of the thyroid glands. As time passes, the glands will usually continue to grow in size, requiring more medication to control the problem. Periodic laboratory blood tests must be performed to track the disease and fine tune treatment protocols. Periodic testing also helps us monitor the appearance of the side effects discussed earlier.

Surgical removal of the thyroid glands is an available option. This surgery is potentially life threatening. The parathyroid glands, which control calcium and potassium levels in the body, are very near to the thyroid glands. If the parathyroid glands are damaged or removed your pet would require a delicate balance of medications to avoid serious problems. It is possible for the thyroid gland to re-grow if not completely excised, which could eventually result in the overproduction of thyroid hormone again in the future.

Radioiodine treatment requires an injection of a radioactive dye into the blood that selectively damages the thyroid tissues and effectively stops the overproduction of thyroid hormone. If all of the thyroid gland is not destroyed by the radioiodine, it is possible for the thyroid gland to re-grow which could ultimately result in overproduction of thyroid hormone again in the future.

Prescription Diet YD has been developed to minimize the ability of the thyroid to produce thyroid hormone. Production of thyroid hormone requires iodine as an essential ingredient. By limiting the amout of iodine in the diet, the thyroid gland cannot overproduce thyroid hormone, so the levels of thyroid hormone in the body are restricted to normal leverls. This means feeding your cat YD removes the cost of radiation therapy and the side effects of oral medications.

On-Going Care for Feline Hyperthyroidism

Because most cats diagnosed with Feline Hyperthyroidism are older, many will suffer from kidney disease as well. Because the disease causes increased blood pressure in most cats, correction of hyperthyroidism can cause a lowering of the blood pressure which can adversely affect the kidney disease. Monitoring this situation with periodic laboratory blood testing and blood pressure monitoring, and controlling the kidney disease with diet and proper dental care is also important.

We will need to recheck your cat’s CBC (complete blood count) and platelet count every two weeks for a period of time. We will then need to recheck the thyroid levels, liver and kidney functions in four weeks. Assuming no problems develop and we are able to continue the medication, we can reduce retesting intervals. If we find that medication needs to be increased in the future, then the retesting protocol will need to be changed.

If you are feeding YD, we just need to periodically test the thyroid hormone levels to make sure they are being properly controlled.

While Feline Hyperthyroidism is a very serious disease, we can greatly improve your cat’s life by appropriately responding to the existing problems. Diagnosis of Feline Hyperthyroidism is just the beginning. Ongoing management of the disease is the true key to success.

The most common symptoms of Feline Hyperthyroidism are:
• Nervousness or hyperactivity
• Weight loss in spite of large appetite
• Increased drinking & urination
• Diarrhea
• Intermittent fever
• Difficulty breathing
• Vomiting
• Signs of cardiovascular disease
• Rapid heart rate
• Hair loss
• Voice changes

A thorough physical examination and laboratory blood tests are used to diagnose Feline Hyperthyroidism. Periodic laboratory tests of both blood and urine are the most effective tools for early detection of any disease.