Hyperthyroidism is the medical term to describe the signs and symptoms associated with an over production of thyroid hormone. Hyperthyroidism is a condition caused by the effects of too much thyroid hormone on tissues of the body.

Increased appetite, unexplained weight loss/loss of muscle mass*, irritability, vomiting, excessive thirst* (polydipsia) , weakness , lethargy.

*if you observe these, mention hyperthyroidism to the veterinarian and have a blood test taken, as they are common indicators

Older cats are especially prone to this ailment. Onset typically begins at ages 11-15 but can be at any age. Heart disease and kidney failure can often accompany hyperthyroidism. Onset can be slow (up to 1 yr to be observed) so quick diagnosis and treatment are essential.

Three tiers of treatment are available: medication, surgery and radioiodine treatment. Medication would have to be taken indefinitely. Surgery and radioiodine offer permanent solutions. Radioiodine can result in the development of hypothyroidism, which can be managed.

Hyperthyroidism is an overactivity of one or both of the thyroid glands in the neck. It is caused by a benign tumor (called an adenoma) of the thyroid gland in almost all cases. This tumor produces excess amounts of thyroid hormone, which circulates through be bloodstream and affects the metabolism of many internal organs. In rare cases a malignant tumor called a carcinoma is the cause. The thyroid glands consist of two flat lobes located on each side of the trachea. They produce two hormones, referred to as T3 and T4 which circulate throughout the body and affect sensors on the organs of the body. Because these glands control the metabolic rate, affected cats will tend to be overactive, eat and drink more than usual, yet lose weight dramatically. If the condition is left untreated, the racing heart becomes unable to cope with the strain, and the cat will die from heart failure. Once hyperthyroidism has been diagnosed treatment can be very successful. The therapy for hyperthyroidism is directed at controlling the excessive production of thyroid hormones.  There are three methods to treat hyperthyroidism: medication, surgical removal and radioactive iodine treatment. Antithyroid drug therapy would be necessary for life, with symptoms of the disease recurring rapidly following discontinuation of the drug. Thyroidectomy is an effective therapy for feline hyperthyroidism.

This facet of Hyperthyroidism impacted the Supreme Wirdle…

 

A relatively common treatment is the use of a drug called Tapazole. It is inexpensive and easy to give to most cats. Disadvantages are the fact that it never cures the problem, so a cat will need to be on it long term, and occasional cats get side effects to the drug. It is used in cats that have chronic renal failure, a common problem as cats age. In these cats the excess thyroxine circulating can actually be an advantage to the kidneys because it increases the blood flow to the kidneys. This makes them more efficient at removing waste products. If we completely destroy the excess thyroid tissue with radiation or surgery, a kidney problem that was under control can now become serious. In these situations we administer a dose of Tapazole that decreases the excess thyroxine enough to make the cat feel a little better, but not so much that it will exacerbate a kidney problem that is being masked. It is a compromise in therapy because it is an attempt to balance two problems that are occurring simultaneously.

 

Because other diseases can show similar signs like diabetes and renal (kidney) failure, it is important to evaluate all of the organs of the body at the same time.

For further reading… a list of resources used in the compilation of this article.

site map