Hyperthyroidism in Cats: an article by Troy Animal Hospital

It’s not uncommon for pets to lose some weight as they age. If you have a senior cat that’s losing weight while still eating as much or more than it once did though, you should consider having your cat’s thyroid level checked.

Hyperthyroidism is caused when your cat’s thyroid, a pair of small glands in its neck, starts producing too much thyroid hormone. There are a number of symptoms besides weight loss that can indicate your cat has an overactive thyroid. Your cat may have some or all of the following symptoms: increased appetite, increased water drinking and urinating, increased heart rate, behavior changes, diarrhea, hyperactivity and weakness.  If left untreated, hyperthyroidism can cause heart disease and high blood pressure, which can lead to damage of the kidneys and other internal organs.

If your cat is exhibiting any of these signs, it’s a good idea to have an examination done by a veterinarian.   Troy Animal Hospital can also do blood work to test for hyperthyroidism in-house, or blood work can be sent to an outside lab. Your veterinarian may wish to do other blood tests to check your cat’s overall health, before beginning treatment for hyperthyroidism.

There are four main types of treatment for hyperthyroidism in cats: daily oral medication, surgical removal of the thyroid glands, radioiodine treatment and diet.  The treatment most people choose is medication. Your cat will take a pill one to two times daily to help control its thyroid levels. Your cat will need to take this medication for the rest of its life to keep their thyroid levels within acceptable limits. Troy Animal Hospital has this medication available for our patients.

While reactions are rare, there are some cats that do not do well on the medication.  A second treatment option is surgical removal of the thyroid glands. This is a permanent cure, although each cat has to be individually evaluated to be certain it is a good surgical candidate. Another treatment option is radioactive iodine therapy.  It involves an injection of a small amount of radioiodine that is taken up by the abnormal thyroid cells, destroying them. It can also be curative, but is only performed at specialized facilities, since it involves the handling and disposal of radioactive substances. While we do not perform radioactive iodine treatments at Troy Animal Hospital , we are more than happy to refer you to several different hospitals that do.

A more recent treatment for hyperthyroidism in cats is a specialized diet that is extremely low in iodine, produced by Hill’s called y/d . Owners that opt to treat their cat’s hyperthyroidism through this diet must be sure that it is the only food they feed their cat, since any other treats or food will provide iodine that the overactive thyroid will use to produce too much thyroid hormone. Troy Animal Hospital offers Hill’s y/d in canned and dry.

Hyperthyroidism is not an uncommon disease in older cats, but with treatment, your cat can continue to live a long happy and healthy life. If you have any questions or think your cat may be suffering from this condition, please feel free to call Troy Animal Hospital at 937-335-8387.