Information for Clients

What is Hyperthyroidism?

The thyroid is an endocrine organ in the body responsible for regulating your cat's metabolism and organ function. Hyperthyroidism is a disease that causes an overproduction of thyroid hormone, making your cat's body work in "overdrive." You may notice your cat losing weight, having a voracious appetite, and being more active. The disease affects multiple organ systems and is fatal to your cat without treatment.

What are My Cat's Treatment Options?

The most commonly prescribed treatment is a daily medication called methimazole (Tapazole™) that your cat must take for the duration of their life. This medication can be useful in controlling your cat's hyperthyroidism, but is also linked to serious reactions and side effects in cats, not to mention the difficulty many owners find in medicating their cat up to twice daily for life. Methimazole only manages the production of thyroid hormone, it does not cure the disease.

Another option is the surgical removal of the diseased thyroid tissue. This option is seldom used in veterinary medicine today due to its relative ineffectiveness, anesthetic risk, and significant post-surgical hospitalization period.

Radioactive Iodine: The Gold Standard

The most effective option to treat your cat's hyperthyroidism is I-131, a radioactive iodine treatment that actually CURES the disease with one treatment in 95% of cats! I-131 is a one-time injection that goes under your cat's skin just like a vaccination. The radio-iodine travels exclusively to the diseased tissue of your cat's thyroid and does not harm the surrounding tissue or other parts of the body. The result is a healthy thyroid and a happy cat with a better quality of life! Recent studies show that cats treated with I-131 live up to 3 years longer than those treated with the medication methimazole alone.

Is I-131 Safe?

Yes! It is actually the safest treatment option for your hyperthyroid cat. There are no known side effects to I-131 therapy compared with medical or surgical treatments. The amount of I-131 administered is calculated specifically for each cat based on several factors, ensuring safe and accurate dosing. Most cats, even those with severe disease, begin to feel noticeably better within 72 hours and have normal thyroid hormone levels an average of 30 days following treatment.

Many people are unsure about a radioactive treatment for their beloved friend. We closely monitor our patients daily and abide by strict regulations set by the Colorado State Department of Radiation Safety. With two board-certified internal medicine specialists, Drs. Ellen Miller and Lauren Prause, and a team of specially-trained nurses, you can rest knowing that your cat will be safe and well cared for in our hands.

What is My Cat's Treatment Like?

Your cat's single injection of radio-iodine is given on the morning of arrival. Our staff provides your cat with compassionate care during the following days.

The length of each cat's stay in our comfortable Radiant Feline ward varies. It is dependent upon the severity of the hyperthyroidism, and thus the quantity of radio-iodine we must administer. It is also dependent upon your cat's individual metabolic ability to uptake the radio-iodine, and then to eliminate the waste through urine and feces. Our average guest stays as few as four days. During your cat's stay, you will receive daily phone progress reports regarding your cat's treatment and well-being.

Where Will My Cat Be Staying?

We understand that your cat is happiest when at home with you, so we do everything we can to make your cat's stay with us stress-free and comfortable. Our special Radiant Feline ward is isolated from the rest of the hospital, providing a quiet environment for your cat's stay. We have a special ventilation system that draws odors away from each individual kennel. In our spacious, two-level kennels, each cat has its own luxury kitty bed, and enjoys listening to soothing classical music during the day! We'll work with you to plan a menu of favorite dishes for your cat's stay with us. We encourage you to bring something that will remind your cat of home; however, any belongings that stay with your cat are not returnable, due to the radioactive nature of treatment.

When Your Cat Goes Home

When your cat is able to go home after treatment, there will still be a low level of radioactivity in the thyroid glands as well as in the urine and feces. For two weeks following treatment, you will need to follow a few simple guidelines to ensure safety for you and your family. If you follow these guidelines, there is no risk to you.

After the two week period, your cat is able to return to a normal routine. At the time of your consultation, we will go over the home care instructions in detail with you and your family and will be able to answer any questions or concerns you may have regarding post-treatment care.

Please call with any questions you have regarding I-131 therapy or to schedule an appointment. We are also happy to send you a detailed information packet in the mail.

If you have already scheduled a consult or treatment date, save time by filling out our Patient Information Form before your appointment!