Palmetto Animal Hospital

Radioactive Iodine

Hyperthyroid treatment puts an end to a lifetime of daily medications, monthly blood panels, and possible surgery for your cat, because it cures feline hyperthyroidism with one injection. The injection is called radioactive Iodine 131 and is administered on a Monday morning. Your feline companion will be monitored in the hospital until Wednesday afternoon as a safety precaution. Once you pick up your pet, there are only a few simple steps to follow for the next few days.

What is Hyperthyroidism?

This endocrine disease is the excess production of thyroid hormone that is secreted by the thyroid gland. In cats, this is usually caused by a benign tumor either on one or both thyroid glands. Rarely, hyperthyroidism is caused by a malignant tumor.

What are the clinical signs?

  • Weight loss
  • Restlessness or increased anxiety
  • Increased appetite
  • Vomiting
  • Diarrhea
  • Hair coat and skin changes

If left untreated, the body cannot keep up with increased metabolic demands, which can lead to multiple organ failure.

What are the current treatment options for Hyperthyroidism?

Palmetto Animal Hospital has extended service beyond the wellness care provided by our family veterinarians. Since hyperthyroidism has now become the most common endocrine disorder in middle to older aged cats, we are providing an additional treatment.

  • Medications (Tapazole/ Methimazole)—The disadvantages are the need for daily medications for life. These medications can have side effects that range from vomiting to the injury of the bone marrow.
  • Surgery—The disadvantages are anesthesia risk, injury to non-thyroid tissue and 70% occurrence rate in the other gland, which requires additional treatment.
  • Radioactive Iodine (I131)—The disadvantage is having to confine the cat at an approved facility until the level of radiation is safe for the owners and other pets. It is usually a maximum of 3-4 days at our facility and then a two-week precautionary guideline should be followed when released to go home.

How does I131 work?

Unhealthy thyroid tissue has an appetite for iodine to make the hormone T4. The healthy thyroid tissue is dormant and does not need to use iodine. When I131 is administered the unhealthy tissue uses this and is destroyed, spares the dormant healthy tissue. The iodine is eliminated primarily through the urine. Over time the dormant tissue becomes active and normal thyroid function returns to 95% of cats treated. The only side effect seen in some cats is mild laryngitis, change in voice or some swallowing difficulty. These symptoms usually resolve in a few days without treatment. Some cats may become hypothyroid (low production of thyroid hormone), but this usually does not require treatment because it usually resolves over time.

What can be expected?

You will receive a packet of information in the mail that goes over details and also includes a consent form. The consent form must be brought in signed on the day of treatment.

Your pet will need to be dropped off the morning of treatment between 7:30 a.m. and 8:30 a.m. Please be prepared to go over information about the treatment before leaving.

The duration of stay is usually 3 days. Families with small children, pregnant household members, or cats released with a higher radioactivity levels will require stricter guidelines upon discharge or additional hospitalization.

Your cat cannot be visited due to strict state and federal regulations. You will be contacted each day with an update.

Sedation may be administered depending on the nature of your cat, so that we can safely administer the I-131.

A deposit will be required prior to ordering the I-131 treatment, as each dose will be specific to your cats needs and cannot be returned.

Follow up blood work will need to be done by your regular veterinarian 30 and 90 days after treatment.

Join the Palmetto Animal Hospital Family Today!

Located just over a mile from the Florence Country Club and Jeffries Creek Park in the Cypress Point neighborhood.

Phone: 843-667-6720

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