PetRadioiodine therapy is widely considered the best treatment for hyperthyroidism in cats: a single injection of radioactive iodine destroys the overactive thyroid tissue while sparing the rest, and most cats are cured. The trade-offs are an upfront cost and a few days of mandatory hospitalization in a licensed facility. Here's the Canadian cost picture and the insurance timing that matters.
What it costs in Canada
| Scenario | Typical cost (CAD) |
|---|---|
| Pre-treatment consult + records review | Moderate — included at most centres |
| Radioiodine (I-131) injection | The core of the cost — dose-dependent |
| Required hospitalization (a few days, isolation) | Included in the all-in price |
| Pre-treatment bloodwork / thyroid panel | Moderate, sometimes separate |
| Additional tests or medication while hospitalized | Variable — possible add-on |
| Daily medication (the cheaper alternative) | Lower per month — but lifelong, with monitoring |
| Managing kidney disease unmasked by treatment | Variable — common in senior cats |
The all-in price covers the dose and the few days of isolation hospitalization that radiation-safety rules require. The reason many owners choose it despite the upfront cost: it can be a one-and-done cure, ending the recurring expense of daily methimazole and the regular bloodwork that medication demands for life. For a cat with years ahead, that often works out cheaper overall.
With insurance vs paying out of pocket
| Scenario | You pay | Insurer pays |
|---|---|---|
| No insurance | The full all-in cost of the treatment and hospitalization | $0 |
| Comprehensive policy (diagnosed after enrolment) | Annual deductible + your reimbursement share | Reimburses 70–90% of the radioiodine treatment after deductible |
| Comprehensive policy (hyperthyroidism pre-existing) | Full cost of treatment | $0 — pre-existing exclusion |
| Wellness add-on only | Full cost — it's treatment for an illness, not preventive care | $0 from wellness portion |
Radioiodine therapy cost by Canadian city
Radioiodine (I-131) is unlike any other treatment here: it uses a radioactive isotope, so it can only be given at a licensed radioiodine facility — and there are only a handful across Canada. Your cat also stays hospitalised there for several days (a regulatory requirement, until radiation levels fall). The all-in price varies little between centres; the real geographic cost is the travel to one and back. Use this as general guidance, not a quote.
| Access | What to expect |
|---|---|
| Near a licensed I-131 centre near vet colleges and specialty centres serving Toronto/Guelph, Montreal, Calgary, Vancouver, Saskatoon | Treatment available; your cat stays several days for the mandatory post-treatment hospitalisation |
| Elsewhere in Canada | No local option — your vet refers you, and you travel to the nearest centre for a drop-off and a later pick-up |
Because the mandatory boarding is built into the price and the facilities are so few, plan the trip: book ahead, confirm the centre's referral process with your vet, and budget for one drop-off and one pick-up journey on top of the treatment fee.
Considering insurance?
Hyperthyroidism is one of the most common conditions in senior cats — and once it's diagnosed, no new policy will cover it or the radioiodine cure. The way to keep this covered is to insure your cat while it's still middle-aged and healthy. Compare Canadian insurers before your cat reaches the high-risk senior years.