Hyperthyroidism is a disease that commonly affects older cats. Hyperthyroidism is caused by an increase in production of thyroid hormones (known as T3 and T4) from an enlarged thyroid gland in the cat’s neck. In most cases, enlargement of thyroid glands is caused by a non-cancerous tumor. Symptoms of hyperthyroidism include: weight loss, increased hunger, thirst and urination. Some people notice that their normally polite cat is now stealing food from the counter or plates due to the increased appetite. Hyperthyroidism can be diagnosed at your regular vet from a simple blood test. There are a few different treatments available.   1. I-131 treatment which is an injection of radioactive iodine that travels to the tumor and destroys it leaving the healthy thyroid tissue intact. This is the gold standard of treatment which in most cases only has to done once. 2. Surgery to remove the tumor. This is not usually done anymore because there are less invasive treatments available. 3. A prescription diet from your veterinarian. This diet restricts iodine. Healthy cats can eat this food also as long as some regular food is given every day. 4. Medication which does not cure the disease but keeps the thyroid functioning at normal levels. This has to be given for the rest of the cat’s life. Some people find pilling a cat twice a day difficult. This medication is also available in different ways if formulated at a compounding pharmacy. These include : cream that is absorbed through the skin, flavored liquid or chew treats. It is important to take your cat to the vet if he or she is showing any symptoms of hyperthyroidism. If left untreated the secondary problems caused by this disease can be serious. If treated early your cat can live a long happy life.