FELINE THYROID CENTER at VSH Palm Beach – Florida
Radioactive Iodine (I 131) is the safest, best, and ultimately least costly lifetime treatment for virtually all hyperthyroid cats. There are no radiation side effects for treated cats, owing to the selective uptake of radioactive iodine by “abnormal” thyroid cells.
Medical Management of Hyperthyroidism:
Antithyroid medications can be used to reduce excessive thyroid hormone secretion. These medications must be given for the rest of the cat’s lifetime. Side effects serious enough to warrant discontinuing using these medicines occur in up to 10 percent of cats. A common misconception about medical management of hyperthyroidism is that it’s the least expensive way to treat the disease. Antithyroid medicines may cost $1.50 to $2.50 per day. Also, the periodic examinations and blood testing required two or three times yearly to accurately and safely dose these medications will cost about $150 to $200 per year. This means an owner will spend $550.00 to $700.00 per year for the rest of the cat’s life to medically manage hyperthyroidism, while at the same time having to go through the daily ordeal of giving medication to their cat.
Surgery to remove the thyroid gland(s) involves general anesthesia risk and can result in serious calcium regulation difficulties after surgery if the parathyroid glands, or their blood supply, are inadvertently damaged during surgery. Following successful surgical treatment for hyperthyroidism, 10-20 percent of cats will become hyperthyroid again in their lifetime.
Radioactive Iodine (I 131) Therapy:
I 131 therapy uses a radioactive isotope of iodine that is administered as an injection under the skin (just like vaccines are given). The I 131 will be taken up preferentially into the “most active” thyroid cells, which are the thyroid cells in the nodule(s) or tumor(s) that are overproducing thyroid hormone. The radiation energy is emitted and absorbed within a few millimeters of where the iodine accumulates in the body and will kill these abnormal thyroid cells. Following I 131 administration, cats are housed in large cages in a shielded radiation safety room for 4-5 days to allow most of the radioactive iodine to be excreted. The stay after I 131 administration is required by Florida Radiation Protection Statutes.
How effective is I 131 therapy?
The first dose of I 131 will cure hyperthyroidism in 97-98% of hyperthyroid cats. 70% of cats have normal thyroid levels (T4) within one week of I 131 therapy. 90% have normal T4 levels by one month and 97% have normal T4 levels by three months. There are a few cats in whom it can take as long as 6 months for resolution of hyperthyroidism. Following successful I 131 therapy, only 0.3% (1 in 300) cats will become hyperthyroid again in their lifetime.
What does the treatment plan include?
Our treatment plan includes a review of records, (including reviewing the x-ray interpretation, echocardiogram, abdominal ultrasound examination), I 131 injection,
daily monitoring (with as much love and care as we can safely give), feeding and hospitalization. Following discharge, we will stay involved in your patient’s health via direct discussions with you and a review of your cat’s post treatment test results.
The FELINE THYROID CENTER at the VSH is an approved and fully licensed specialty facility with State Department of Health and Bureau of Radiation Control permits for use of I 131. We are privately owned and operated, with a Radiation Safety Officer on premise.