Radioactive iodine (I-131) is the gold-standard treatment for feline hyperthyroidism. At Takurua Vets we offer this advanced therapy on-site, giving cats a safe, effective and often permanent cure with a single injection.
Hyperthyroidism is caused by overactive thyroid tissue producing excess hormone. Over time this places strain on the heart, kidneys and other organs. While medication or prescription diets can manage the condition, I-131 directly targets the abnormal thyroid cells and resolves the disease in 95-98% of cases, without ongoing daily treatment.
Hyperthyroidism in cats can be managed in different ways, and the right approach depends on the cat, the household, and what treatment goals are most important. Medical treatment can help control thyroid hormone levels, while radioactive iodine treatment aims to cure the disease by targeting the abnormal thyroid tissue directly.
Anti-thyroid medication can be an effective way to manage hyperthyroidism, particularly when owners want a non-curative option or when a cat needs stabilisation before longer-term treatment decisions are made. Medication does not remove the abnormal thyroid tissue, so it usually needs to be given on an ongoing basis.
Many cats are now treated with I-131 because it offers a curative solution in the majority of cases without the need for surgery or anaesthesia. The treatment is delivered as a painless single injection, similar to a vaccination, and once cured most cats no longer require daily medication. When cats are appropriately selected, side effects are minimal, and as thyroid levels stabilise they often feel brighter, calmer, and return to their normal behaviour.
Your cat is admitted to Takurua Vets and receives a small injection of radioactive iodine under the skin. After treatment, they stay in our purpose-built isolation ward for around 7 days while the radioactivity naturally decreases to safe levels.
Our team monitors your cat closely throughout their stay and ensures they are comfortable, calm and well cared for.
If you’d like to understand what the process looks like before making a decision, you can watch our walkthrough video showing our facilities, isolation ward, and how cats are cared for during treatment.
Once discharged, only simple precautions are needed for around two weeks, such as limited close contact and minor litter-handling changes. We provide clear, easy-to-follow instructions at discharge and are available to answer any questions.
Extended boarding options are available if you would prefer additional time before your cat returns home.
Does my cat need anaesthesia?
No. The injection is painless and does not require sedation.
Is I-131 safe?
Yes. Side effects are uncommon. Some cats may develop mild hypothyroidism, which is usually temporary or easily managed.
What about kidney disease?
Hyperthyroidism can mask underlying kidney disease. Treating the thyroid condition is still recommended, as leaving it unmanaged places additional strain on the kidneys.
How much does treatment cost?
The current cost at Takurua Vets is $1500, including the admit consult, treatment and 7-day isolation stay. Blood tests are usually arranged with your regular vet clinic.
Can all cats receive I-131?
Most can, but a health assessment is required. Please contact us to discuss whether your cat is a suitable candidate.
Many owners first learn about hyperthyroidism after noticing weight loss, increased appetite, restlessness, thirst changes, or a cat that simply seems older and less settled than before. The pages below explain what hyperthyroidism is, how it affects the body, and why treatment can make such a meaningful difference.
Learn what feline hyperthyroidism is, what signs it can cause, how it affects the heart and kidneys, and how diagnosis and treatment are usually approached.
Learn why weight loss in older cats should not be ignored and how thyroid disease can be one of the important causes.
Learn why some owners look for alternatives to long-term daily treatment, and how curative options like I-131 can sometimes change the plan completely.
Whether you are a cat owner considering treatment or a veterinarian looking to refer, our team is happy to talk through the process and answer any questions.
I-131 is available by referral. We welcome discussion on individual cases and will coordinate medication withdrawal and admission directly with clients.
Please contact the clinic if you would like to refer a patient or discuss suitability.
