Radioactive Iodine Therapy (I131)
Hyperthyroidism is a common disease in older cats. It is caused by a tumor of the thyroid gland, which though usually benign, causes an overproduction of thyroid hormone. The excess thyroid hormone causes an increase in the cat’s metabolism, leading to weight loss, gastrointestinal symptoms including vomiting and diarrhea, and heart disease.
Many cats respond well to medical therapy for hyperthyroidism. However, some cats develop side effects to the medication and cannot tolerate the lifelong treatment. Other cats are just too difficult to give pills to every day.
Medications may offer control of the condition in many cats but side effects from the medication may occur and can be a difficult and labor-intensive option requiring lifelong treatment. Surgical removal of the thyroid glands has been another option but this comes with risks including the potential damage to vital nearby glands. Radioactive iodine therapy replaced both of these options as the gold standard for treatment of hyperthyroidism.
Radioactive Iodine, when administered by an injection, is taken up by the thyroid gland, allowing irradiation of just the diseased thyroid. In almost all cats treated, this leads to full removal of their symptoms. The radioactive iodine is eliminated from the cats’ bodies through their urine.
While the treatment is safe for the cats, they must remain in the hospital until the level of radioactivity has diminished to the point where they can safely be with their family again. This usually takes between six and eight days.
Owners find that their cats return to a normalized lifestyle after the treatment and they express a significant increase in their pet’s quality of life.
Because of the radioactive nature of the Iodine used, this procedure can only be done at specially licensed facilities. The vets and staff at Ocean State Veterinary Specialists have pursued the required advanced training and licensing to offer Radioactive Iodine therapy. If your cat has hyperthyroidism and you would like to consider this procedure, speak with your family veterinarian about a referral to OSVS.