As cats age, various disease processes have the potential to develop. Several common ones are sugar diabetes, kidney disease, dental disease and heart disease. Another condition, feline hyperthyroidism, has also become a problem in cats as they get older.

In this disease, the thyroid gland secretes an excess amount of a hormone called thyroxine. Thyroxine affects the metabolism of all organs, so excess can result in many different problems. Common symptoms are weight loss, vomiting and diarrhea. Some of these cats eat excessively yet lose weight. Some will even drink and urinate excessively. Others may seem agitated or restless. As the disease progresses, it can lead to heart failure and blindness.

During a physical exam, we can sometimes feel an enlarged thyroid gland, although a normal-feeling gland can also have the problem. We might also detect a rapid heart rate and even notice problems with the retina. A blood sample is an excellent way to check for excess thyroid hormone. One of the most accurate ways to diagnose this problem is to do a radionucleotide scan of the gland. With this test, we can actually visualize the gland and see the problem area.

This disease is treated in several ways, depending on many factors. Tapazole is a medication that is frequently used because it will lessen the amount of excess thyroxine in the bloodstream. It will not cure the problem, so it will have to be administered for the rest of your pet’s life. In addition, it has the potential for side effects. Your vet needs to monitor your pet every three to six months while it is on Tapazole therapy.

Another treatment, and one that will cure the problem, is to give radioactive Iodine that destroys only the part of the thyroid gland that is responsible for the excess production. This is the treatment of choice in most cases. Your pet will need to be sent to a specialist for this treatment.

Feline hyperthyroidism is a complicated disease with many manifestations. Please read our webpage for all the details.