Radioactive iodine (I-131) cost for cats
Radioactive iodine cures most hyperthyroid cats with a single treatment. The upfront cost is higher than pills, but there's no daily medicine afterward.
Last updated: October 2026 · US prices · 6 sources · see sources
What it costs
| Item | Typical US price | Src |
|---|---|---|
| Treatment center, total | $1,900.00 to $2,100.00 | [1] |
| Specialty hospital, treatment fee | $1750 | [2] |
| Iowa State, workup and therapy | $3,000 to $3,500 | [3] |
| University of Tennessee | $3,300.00 – $4,750.00 | [4] |
| Radioactive iodine (RealVetCost) | $1,500–$2,200 | [5] |
Each source measures something a little different: published clinic prices, national averages or real owner bills. Use them to plan, and ask your vet for a written estimate.
What it is
The cat gets one injection of radioactive iodine, which destroys the overactive thyroid tissue. The cat stays in a licensed isolation ward for several days until radiation levels drop. [6]
When vets recommend it
It's an option for cats diagnosed with hyperthyroidism, after tests to check the kidneys and heart. [6]
Recovery and aftercare
Follow-up bloodwork at your regular vet checks that thyroid levels have come down. [6]
Medicines vets often use around this treatment: Methimazole. We don't list doses; your vet will decide what fits your pet.
What affects the cost
- Who does it Board-certified specialists and referral hospitals usually charge more than general practices.
- Your pet's size and health Bigger pets need more anesthesia and medicine, and pets with other illnesses may need extra tests or monitoring.
- Planned or emergency Emergency and after-hours care costs more than a scheduled procedure.
- Where you live Prices in big coastal cities tend to run higher than in smaller towns.
Common questions
How much does radioactive iodine (I-131) for cats cost?
Treatment center, total: $1,900.00 to $2,100.00. Specialty hospital, treatment fee: $1750. Your vet's written estimate is what counts, since prices vary by clinic, region and your pet's needs.
Will pet insurance pay for it?
Many accident-and-illness plans help with treatment like this if the problem isn't pre-existing and any waiting period has passed. Check your policy, and ask your vet for an itemized estimate you can send to the insurer ahead of time.
Related
This page is general information for pet owners, not veterinary advice. Talk to your vet about your own pet.
Sources (6) — tap to show
- Feline Hyperthyroid Treatment Center – Cost of treatment
- PVESC – Radioactive iodine therapy: admission information and cost
- Iowa State University Lloyd Veterinary Medical Center – Feline I-131 therapy
- University of Tennessee College of Veterinary Medicine – Iodine 131 feline pre-treatment information and estimate (PDF)
- RealVetCost – Hyperthyroidism in cats: symptoms, treatment & costs
- Merck Veterinary Manual (pet owner version) – Disorders of the thyroid gland