Radioactive Iodine Treatment for Cats

Radioactive iodine therapy is a safe and effective treatment for hyperthyroidism.
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Your furry companion's hyperthyroidism can be a source of stress for you, and so can its treatment. Radioactive iodine treatment might sound scary, but it's actually one safe treatment option your veterinarian may suggest that could cure him of the disease.

What Is Hyperthyroidism?

The thyroid is a small gland in Kitty's neck that regulates his metabolism, affecting almost all the organs in his body. Hyperthyroidism is a disease that usually affects cats over 12 years old -- it occurs when his thyroid gland is enlarged and overactive, producing too many thyroid hormones. This usually happens because he has a benign tumor on this thyroid gland. According to the Cat Health Guide, only 2 percent of cases involve a malignant tumor. If left untreated, hyperthyroidism can cause damage to kitty's eyes, kidneys, heart and brain.

What Is Radioactive Iodine Therapy?

Radioactive iodine therapy is a treatment method preferred by vets. It involves a single injection of radioactive iodine. The substance circulates in his bloodstream and targets his thyroid. Since only his thyroid will absorb the substance, it won't affect any of the other organs in his body.

While the idea of injecting your cat with something radioactive might cause you some anxiety, the low levels pose no serious health risk to Kitty. In fact, the procedure is nearly identical to a similar treatment for humans.


The most important advantage of this treatment is that radioactive iodine therapy can cure Kitty of hyperthyroidism. He can have normal hormone levels as little as one week after treatment. It doesn't come with the risks that anesthesia presents, since anesthesia is not needed; essentially Kitty is just receiving another shot like when you got him vaccinated. It also doesn't pose the risk of accidental damage to surrounding glands like traditional surgery.


Your cat may not be able to get the treatment at his regular vet office; it requires a special hospital licensed to use radioisotopes. Your cat will have to spend about two weeks in the hospital afterward. While the use of the radioactive iodine is safe, Kitty is kept isolated afterward, as a safety precaution, until his radiation level is low enough for you to cuddle with him. Be aware that they probably won't let you visit him until it's time to take him home, which can be worrying for pet parents.

Perhaps the biggest drawback is that the treatment and time spent in the hospital could get pricey, so it may not be in your budget. Speak with his vet to determine if radioactive iodine therapy is the best treatment option for you and your feline pal.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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