Feline Radioactive Iodine (I-131) Therapy at ISU Lloyd Veterinary Medical Center
What to Expect:
Before Treatment
Before radioiodine (I-131) therapy for feline hyperthyroidism at ISU, your cat will undergo an initial screening appointment. During this appointment, we will assess your cat's overall health through a physical exam, basic lab tests, blood pressure measurement, and possibly an echocardiogram. Additional tests may be recommended based on your cat's health. Initial appointments are scheduled on Mondays or Tuesdays.
Can Cats Be on Methimazole Before Referral?
Your cat should continue its hyperthyroid treatment (methimazole or Y/D diet) until its screening appointment. However, cats must stop methimazole at least 7 days before being seen for the treatment appointment (preferably 10-14 days before). In addition, cats on Hill’s Y/D food should transition back to a regular diet at least 1 week before treatment. Once a date has been set for your cat’s treatment appointment, we will provide you with a specific date to discontinue either methimazole or change diets.
What Comes Next?
After the screening, your cat will return for thyroid scintigraphy and I-131 administration. Scans are usually done on Wednesdays, followed by I-131 treatment the following day. I-131 is given as a single, subcutaneous injection.
Hospital Stay
Following treatment, cats typically stay in the hospital for 4-5 days, usually being discharged the following Monday. We will update you daily on your pet's health, but visits are not allowed during this time. Toys or blankets cannot be brought into radiation isolation.
Discharge Instructions
Before discharge, you'll receive detailed instructions and a waste receptacle for handling your cat’s waste. Cats must be transported in a carrier and handled with latex gloves. During the ride home, place the carrier on the back floorboard or seat—avoiding direct contact with your pet.
Post-Treatment Care
At home, minimize contact with your cat, especially in the first two weeks. Use latex gloves when handling the cat or waste for six weeks, and follow special waste storage procedures.
Cost: The estimated cost for complete I-131 workup and therapy ranges from $3,000 to $3,500.
Follow-Up: Recheck evaluations with your referring DVM are recommended at 6 weeks and 3 months post-discharge.
For more information or questions, please contact ISU-VMC at 515-294-4900.