Can Cats Recover From Hyperthyroidism?

Hyperthyroidism is most common in cats over 12 years old.
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Receiving a diagnosis for hyperthyroidism for your furry loved one is frightening. It can feel like you could possibly lose your best four-legged friend. However, with proper treatment hypothyroidism can be cured and kitty can make a full recovery.

What is Hyperthyroidism?

Hyperthyroidism, also called thyrotoxicosis, occurs when kitty has increased production of thyroid hormones due to an enlarged thyroid. This is usually caused by an adenoma, or tumor, on his thyroid gland. In a large majority of cases, such a tumor is benign, or noncancerous. According to the Cat Health Guide, only 2 percent of cases involve a malignant, or cancerous, tumor. The disorder is most likely genetic.

Kitty is most at risk for hyperthyroidism when he is over 12 years of age. Pay attention if the cat begins eating like Secretariat but loses weightm as this is most common symptom. You may also notice him visiting the litter box more often to pee, drinking a lot of water, vomiting, suffering from diarrhea or being hyperactive.

Since thyroid hormones affect nearly every part of a cat's body, hyperthyroidism can lead to secondary diseases, most notably enlargement of the heart, hypertension and heart failure. For kitty to beat the disease, begin one of three treatment options as soon as possible.


Medication is the cheapest and most readily available treatment for hyperthyroidism. Thyroid medication works by reducing the amount of hormones the thyroid produces. It typically involves having to give your kitty a pill twice a day. While affordable, this treatment option does not cure the disease, it only treats the symptoms. Medication is a good option for short-term management, but not long-term. Long-term treatment could involve giving Kitty pills every day for the rest of his life. Such medicine sometimes causes side effects such as vomiting, loss of appetite, fever, anemia and lethargy.


Your vet may recommend a thyroidectomy, a surgery to remove the affected part of kitty's thyroid. The main advantage of surgery is it provides a cure that usually eliminates the need for him to be on medicine for the rest of his life. It is a pretty straightforward surgery whose success rate is high. If both lobes of kitty's thyroid are affected, his vet may want to do two surgeries, removing part of the thyroid each time. There is slight risk with anesthesia, especially in an older kitty who has heart, kidney or other health issues. The greater risk is accidental damage being done to the parathyroid glands, which sit in close proximity to the thyroid and maintain blood-calcium levels. After surgery, Kitty will probably need to spend the night at the vet and be home the next day.

Radioactive Iodine Therapy

Radioactive Iodine Therapy is becoming the preferred treatment by vets to treat hyperthyroidism. Your cat will receive a shot of radioactive iodine into his bloodstream. The iodine is absorbed by the thyroid but none of his other tissues. The radioactive material destroys the affected thyroid tissue but won't harm any other parts of his body. It doesn't require Kitty to be anesthesized, has no serious side effects, and can completely cure him in as little as two weeks after treatment.

Kitty will have to spend about two weeks in the hospital after treatment until the radioactivity levels have fallen. While there is no significant risk from the low levels of radioactive materials, this is done as a precautionary measure for you and anyone else who will cuddle kitty. It can mean treatment and hospitalization can get pricey. Speak with his vet to see which is the best treatment option for your fur ball.

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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