Hyperthyroidism In Cats

Hyperthyroidism is the most common endocrine disease in cats. Feline hyperthyroidism causes higher than average levels of thyroid hormones thyroxine and triiodothyronine. Hyperthyroidism may originate in the endocrine system, but it has an impact on other systems of the body.

The symptoms of feline hyperthyroidism are weight loss, increased appetite, and hyperactivity. The feline hyperthyroidism symptoms of weight loss and increased appetite may be the first signs that something might be wrong. Even though the cat may be eating more than usual, the cat with hyperthyroidism is losing weight instead of gaining weight. Apathetic hypothyroidism is a more rare form of hyperthyroidism in which the cat loses its appetite and is depressed instead of being hyperactive and having an increased appetite.

Hyperthyroidism usually occurs in cats that are middle aged or older. Other signs of feline hyperthyroidism are increased thirst and urination. This may be due to increased blood flow to the kidneys that is caused by hyperthyroidism in cats. A cat owner may notice other feline hyperthyroidism signs including occasional vomiting and diarrhea.

The veterinarian may discover other signs of hyperthyroidism in cats including increased heart rate, congestive heart failure, or arrhythmias. Congestive heart failure is a dangerous and potentially fatal feline hyperthyroidism symptom. A high percentage of cats with hyperthyroidism will develop heart disease. Most of these cases of heart disease can be effectively treated, but some cats will succumb to congestive heart failure.

Diagnosing hyperthyroidism in cats is done with blood tests to measure the levels of thyroid hormones in the blood or with thyroid imaging. The goal of treatment for feline hyperthyroidism is to reduce the production of the excess thyroid hormones. Treatment methods include surgery, antithyroid medications, and radioactive iodine.

If medication is chosen for the desired treatment method, the cat owner should understand that the cat must take the medication for the rest of its life. Radioactive iodine is often the treatment method of choice even though hospitalization is required after the procedure until the cat’s body is clear of radioactive material. Radioactive iodine may cure the cat of the hyperthyroidism so that the cat will need no further treatment.