Indoor cats, that have had good care (both medically and nutritionally), have a lifespan of approximately 12-15 years.  As any kitty parent knows, older cats have their “quirks”.  Your once crazy cat that chased anything not tied down, is now content sunbathing through on the blanketed side of a window.  So what happens if one day you wake up to find your little old-timer filled with the energy of a newborn bundle of fur?  If there have been no changes in his life, like a new diet or the introduction of a younger buddy, you may want to ask your vet about Hyperthyroidism.


Hyperthyroidism, or overactive thyroid, is a very common disorder in older cats (over 7 years).  The butterfly-shaped gland, known as the thyroid, controls the body’s metabolic rate and general activity level.  An overactive thyroid causes the body to experience a fast burn of energy and rapid weight loss, despite an increased appetite.  The growth of a benign tumor on the thyroid gland is usually the culprit of Hyperthyroidism in cats (malignant tumors on the thyroid gland, fortunately, are very rare).  When treated early, your cat has a good chance to be minimally affected by this issue.


What are the symptoms of Hyperthyroidism in cats?

*Increased appetite


*Unexplained weight loss

*High blood pressure


*Increased heart rate/metabolism


Your veterinarian can easily diagnose feline Hyperthyroidism with a simple blood test and/or a physical examination.  If your vet determines that your cat has an overactive thyroid, there are a few different options for treatment.


Option #1: Drug Therapy/Medical Management



*In clinical trials of the drug, Methimazole (as a treatment of Hyperthyroidism in cats), the majority patients are able to manage the condition with this prescription drug treatment.


*Economical and readily available



*As with all chemical therapy, Methimazole can produce side effects (mostly mild)


*Not a curative treatment option – lifelong management


*Requires careful blood monitoring to identify elevated liver enzymes.  It is important to note that sometimes Hyperthyroidism will mask the symptoms of kidney disease in older cats.  The increased blood flow, as a result of an overactive thyroid, may temporarily improve kidney function.


Option #2: Surgical Removal of the Affected Thyroid Tissue (Thyroidectomy)



*A curative treatment option





*This very complicated surgery should be performed by a highly-skilled surgeon that has had extensive experience with removing thyroid tissue.  Delicate care is required to avoid causing damage to the parathyroid glands (essential for maintaining blood calcium levels)


Option #3: Radioactive Iodine Therapy



*A curative treatment option


*No anaesthesia is required to perform the procedure


*Proven effective in treating all affected thyroid tissue at once, regardless of its location


*Simple, one-injection treatment has been shown to cure hypothyroidism in 95% of patients



*Besides the creep-factor of hanging out with your radioactive cat, this option is very expensive which has made it challenging for pet parents to find licensed facilities that perform this type of treatment.


*Once your cat has been injected, he will have to endure an extended hospital stay until his radiation levels fall within normal limits.  The time frame will vary with each cat, but is typically from 10 days to 6 weeks.


Option #4: Natural/Integrative Medicine



*Natural treatment does not have chemical side effects


*Nutritional supplements, homeopathics and herbs can be used in tandem with conventional treatment options as a way to support your pet’s natural healing process


While Hyperthyroidism is a serious condition, it is treatable.  Staying informed about potential health issues is important because early detection tends to deliver the best outcome.  As with all diagnosed conditions, Wisconsin Pet Care urges you to work with your veterinarian to uncover the best treatment option for your pet.