Radioactive iodine (i-131) therapy is a highly effective, minimally invasive treatment for feline hyperthyroidism. Administered as a single subcutaneous injection, i-131 targets and destroys overactive thyroid tissue while sparing healthy cells, offering a permanent cure in over 95% of cases. Unlike medications or surgery, this sophisticated treatment avoids ongoing management and risks associated with other therapies. i-131 is safe, with minimal side effects, and allows cats to return to their normal routines quickly after a brief isolation period for radiation safety.
Please consult the information for owners section for more information and tips on how to discuss i-131 therapy with your clients.
Ideally hyperthyroid patients should have been treated with Methimazole/Thiamazole/Carbimazole for at least 1 month prior to referral.
T4 + Renal values should be evaluated after 1 month of treatment. Patients with no co-morbidities, good clinical response to initial treatment, that are non-azotaemic once T4 levels have normalised are ideal candidates for i-131 therapy.
Medications will need to be stopped for a minimum of 7 days before i-131 treatment, ideally 14 days if this doesn’t clinically compromise the patient. We will organise this with the client during the referral process.
Minimum tests: Initial biochemistry including T4, BUN & Creatinine Levels. Urine specific Gravity (USG)
Ideal tests: T4 levels pre treatment and > 1 month after Methimazole/Thiamazole/Carbimazole treatment was initiated. Full biochemistry profile equivalent to Idexx Chem 15, SDMA, CBC, USG + Dipstick
It is worth noting that i131 could still be performed on patients that has not been previously treated for hyperthyroidism, if you are unsure if a patient is a suitable candidate please get in touch using the form below or giving us a call.
