Could your cat be suffering from hyperthyroidism?
Hyperthyroidism is a condition in which the thyroid glands in the neck develop abnormal tissue and produce too much thyroid hormone, causing bodily functions to speed up. The underlying cause is unknown but in rare cases cancer can cause the condition.
When the thyroid glands don’t produce enough hor-mone it’s known as hypothy-roidism, or an underactive thyroid. As a naturally occu-rring condition, this is very uncommon in cats, although it may be seen as a conse-quence of some treatments, and responds well to thyroid supplements.
The thyroid hormone has many functions in the body so symptoms of hyper-thyroidism may include:
An increase in appetite
Restlessness or an increa-se in activity
A poor coat with possible hair loss
Vomiting or diarrhoea
Urinating in different locations around the house (outside of the litter tray)
Rapid heart rate
High blood pressure
Your vet will suspect hyperthyroidism based on your cat’s symptoms and a physical examination. Levels of thyroid hormone can then be measured by a blood test to diagnose hyperthyroi-dism. Other tests may be taken to look for other diseases which may affect the condition. One difficulty is that changes in the body which occur because of hyperthyroidism (parti-cularly high blood pressure) can mask early kidney disease. This may be revealed when hyperthy-roidism is reversed by treatment but often can’t be seen on tests prior to treat-ment.
Hyperthyroidism is easily treated with a daily dose of anti-thyroid medication. Tablets and a liquid are available but do not cure the condition, only block the excessive production of thyroid hormone, and need to be given lifelong, usually two or three times daily, at regularly spaced intervals (eg first thing in the morning, early afternoon and last thing at night). Many cats live long and happy lives with medication to keep hyperthyroidism under control but regular visits to the vet and monitoring tests are often necessary.
A common solution for cats suffering with hyperthyroidism is to surgically remove the affected tissues, an operation which is known as a thyroidec-tomy. It often provides a long-term or permanent cure in most cats.
Radioactive iodine therapy
Radioactive iodine therapy is given with a simple injection under the skin and then absorbed by the abnormal thyroid tissue. It then destroys the affected tissues without damaging the surrounding glands or tissues. It’s a safe an effective treatment and in many cases provides a cure. But this is only available at some specialist centres and is expensive, and requires your cat to be hospitalised for three to six weeks.
Controlling levels of iodine (which the thyroid gland needs to make the hormones) in the body with a special diet can also help to control the disease in some cases but it is essential that the cat eats only that diet and nothing else This can be tricky if your cat goes out.
Why is it so important to treat
Cats that have hyperthy-roidism not only have a reduced quality of life but, if untreated, the condition can result in heart failure, blind-ness or death. It is therefore recommended that you take your cat straight to the vets if you spot any signs of hyperthy-roidism.