Hyperthyroidism is a relatively common condition of older cats and something that our own practice cat, Jim, suffers from. It is caused by overproduction of thyroid hormone by the thyroid glands which are found in the neck. When Jim first came to us in 2007 we noticed that he was quite skinny yet he had a large appetite so we ran some tests and confirmed that he is hyperthyroid. A good appetite despite loosing weight in an older cat is highly suggestive of this disease. Other common signs of hyperthyroidism include increased thirst and urination, diarrhoea, increased in activity or being hyperactive, vomiting and a rapid heart rate.
Hyperthyroidism is diagnosed by a blood test which can be run the same day at the surgery. It is important when we suspect hyperthyroidism that we also run a full blood screen to check for any other concurrent illness such as kidney failure as this may alter our treatment. Luckily, all of Jim's other results were normal so we started him on medication to reduce the levels of thyroid hormone in his blood. This means that he has to have a tablet every morning for the rest of his life but as you can see since starting on treatment Jim has put on a lot of weight (sometimes a bit too much!) and can lead a normal life. Mostly this involves lying on the windowsill in the sunshine or on the desk in the office, and convincing the nurses that he hasn't been fed yet (on a good day he can manage at least 2 breakfasts and 3 dinners!).
Jim has done very well on treatment but it is still very important for us to monitor the levels of thyroid hormone in his blood as well as his kidney function and blood cells every few months to make sure we are giving him the correct dose of medication and keep him in tip top condition!
An excellent resource on hyperthyroidism can be found at the Feline advisory Bureau website (of which we are proud to be members)
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