Radioactive Iodine Treatment for Hyperthyroidism

In older cats, the overproduction of thyroid hormone is one of the most commonly diagnosed diseases. One in 300 cats overall is hyperthyroid, with an average age of thirteen. Hyperthyroidism is caused by a benign growth in the thyroid gland that is over-producing thyroid hormone. These tumors are almost always benign and represent a form of goiter rather than a form of cancer. Only 1% to 2% of hyperthyroid cats have a cancerous thyroid growth. When a cat produces too much thyroid hormone, its metabolic rate soars to the point where it can burn off more than half of its body weight. Affected cats will have weight loss despite excellent appetite. Increased water consumption, increased urination, vomiting and diarrhea are also symptoms that are seen in cats with hyperthyroidism. If thyroid production is not kept in check, hypertension, heart and liver problems develop, and the cat dies.

Fortunately, hyperthyroidism can be treated successfully. Due to the seriousness of the disease, most veterinarians now screen all cats above the age of eight years for elevated thyroid levels. The earlier the disease can be diagnosed and treated the better the chance of avoiding permanent damage from elevated thyroid hormone levels.