Feline Heperthyroidsm

This week we are going to focus on the well respected senior feline population, that tends to suffer from a condition known as Feline Hyperthyroidism.

The thyroid glands are organs situated in the neck and secret hormones that are responsible for the pace of all of the processes in the body (also known as metabolism).

Hyperthyroidism is a condition in which the thyroid gland produces exess of its hormones and every function of the body tends to speed up resulting in multisystemic disease.

Hyperthyroidism is probably the most common endocrine (hormonal) disorder in cats. It occurs in middle age-older cats, with no breed or sex predilection.

In the vast majority of cases the increased thyroid hormone production is due to a benign (non-cancerous) change but a malignant (cancerous) tumor known as a thyroid adenocarcinoma can also be an underlying cause of some cases of hyperthyroidism.

Cats affected with hyperthyroidism usually develop a variety of clinical signs, which are usually quite subtle at first, but then become more severe as the disease progresses

The most common symptomes are- weight loss despite an increased appetite. Many cats are also showing restlesness, increased drinking and urination, intermittent vomiting and diarrhea.

The multysystemic effects of hyperthyroidism leads to variety of symptoms depending on the affected organ. Also, as this disease occurs mostly in older cats, some affected cats will have other diseases that can complicate and even mask some of the clinical signs.

The most common secondary complications of hyperthyroidism are high blood pressure, heart failure and kidney failure.

In my experience, unfortunatley many cats are diagnosed much too late when they have one of the most devestating outcomes of the┬áheart dysfunction, associated with hyperthyroism – back legs paralysis resulting from a blood clot lodge in the main blood vessel supplying the back legs. This condion has a very poor prognosis for recovery.

Hyperthyroidsm is easily diagnosed by a blood test, measuring the level of the hormones associated with the thyroid gland. On physical examination, one or two enlarged thyroid glands can often be felt as a small, firm mass in the neck.

A general blood and urine tests are also recommended in order to assess the secondary effects on the body organs.

Blood pressure should also be checked with hyperthyroid cats, and if secondary heart disease is suspected then an electrocardiogram (ECG), and a chest X-ray or ultrasound may be helpful.

The most common treatment for hyperthyroidism includes either surgical removal of the thyroid gland or life long antithyroid drug addministration. Radioactive iodine therapy also exists but it is not readily available in most of the veterinary practices.

Clinical signs associated with hyperthyroidism can be quite dramatic and cats can become seriously ill with this condition. However, if diagnosed on time, in most cases hyperthyroidism is controllable and prolongation of life, with good quality of life is possible.

If you recognize any of the symptoms mentioned- mainly weight loss despite an increased appetite contact your veterinarian.