Radioiodine Therapy (I-131) for the Treatment of Hyperthyroidism in cats
Radioactive iodine therapy (I-131) is considered the most e ective treatment for feline hyperthyroidism and Avets is licensed to perform radioactive iodine therapy for feline hyperthyroidism.
A complete blood count, chemistry panel, total T4 and urinalysis must be performed within a month prior to treatment.
A thorough pre-treatment consultation is performed to con rm the cat is a good candidate prior to every treatment. Methimazole is usually discontinued 7-10 days prior to the treatment to optimize the results of radioactive iodine treatment.
Patients receive a dose of I-131 subcutaneously and then remain at Avets in a designated ward until a low level of radioactivity is achieved (usually 1 week). All treatments are administered by Avets’ board-certi ed internal medicine specialist. The pet is discharged to the owner with instructions on post-treatment care in the home to avoid excessive exposure and ensure adequate monitoring for the patient.
Most (>95%) cats are cured of the disease with one treatment. A few cats will require a second treatment, and a very small number have a malignant tumor that will require surgery or referral to centers approved to administer higher doses of I-131.
Post-treatment information for pet owners
For two weeks after discharge, the pet should be con ned to the home. During this time, interactions with the pet should be minimized. The pet should not be held, allowed to sit on or next to any individual, or sleep on a bed with anyone. It is ideal that the pet be con ned to an unoccupied room during this time.
Anyone who is pregnant or under the age of 18 should not directly interact with the pet and exposure to other animals in the household should be limited. The pet should not be permitted to walk on countertops or eat o of plates. All bedding, toys, or potentially contaminated materials should be isolated for three months or washed thoroughly.
A litter box containing dust free litter should be provided in an area where children and other pets cannot be exposed. Soiled litter will need to be discarded in sanitary sewage system (toilet) daily or dirty litter should be double bagged and stored in a low tra c area for a minimum of 3 months before being discarded. Plastic liners should be used to prevent accumulation of radioactivity in the litter box.
If the pet needs veterinary care during the restriction period, it should be provided by Avets to regulate the potential radiation exposure to caregivers. Repeat lab work will be needed at 1, 3, and 6 months after treatment. This can be performed by the primary care veterinarian.