Hyperthyroidism in Cats: Causes and Treatment

You may be surprised to learn that cats can suffer from hyperthyroidism as well as usm as well.
Hyperthyroidism in Cats: Causes and Treatment

Last update: 02 February, 2019

You may be surprised to hear that our pets can also suffer from hyperthyroidism, but it’s true. In today’s article, we’re going to talk about hyperthyroidism and cats.

To start with, let’s see what this disease is and how it can affect our cats.

What is hyperthyroidism?

A sleepy cat laying down.

Hyperthyroidism occurs when the thyroid gland is working excessively.

This overworking produces too many of the hormones that are responsible for controlling many of the body’s functions. This excess makes the body “lose control”, and can cause many different illnesses.

According to veterinary experts, 1 in 10 cats suffer from this disease. And, as with humans, it causes very serious health problems. 

However, despite the fact that their health can worsen at an alarming rate, the condition can usually be controlled. In most cases, vets will prescribe treatments that will cure the animal.

What causes hyperthyroidism in cats?

The acceleration of the thyroid gland also causes an acceleration in the cat’s body. This will speed up its metabolism and it’ll burn energy faster, resulting in noticeable weight loss. However, its appetite will increase at the same time.

Although it has been shown that malignant tumors can cause hyperthyroidism, this only happens in 2% of cases. The general cause of the condition is still unknown, as none of the animals affected by it show any common traits.

As for your animal’s appearance, its hair will start to lose its shine and strength.

The animal will be constantly thirsty, and will urinate more frequently as a result. Its behavior may also change drastically. If it’s a young cat, it may suddenly start to show more signs of age. If, on the other hand, it’s an older cat, it might suddenly recuperate the same energy it had when it was a kitten.

Some abnormal side-effects that can happen in some cases are weakness, vomiting and diarrhea, depression, stress, and breathing problems.

Treatment for hyperthyroidism

Fortunately, hyperthyroidism in cats doesn’t need to be deadly. This is because there are effective treatments for it, like:

  • Medication
  • Surgery
  • Radioactive ions

Like all treatments, they have their pros and cons:

A cat receiving medical treatment.

  • Medication, for example, is very effective at controlling the thyroid hormones your body produces. It can make everything return to normal, and have the thyroid functioning normally again. However, it’s not a cure for the disease. Therefore, if you choose this option, you should know that your cat will need to take this medication for the rest of its life.
  • Surgery will eradicate the problem. With just one simple operation, the vet will remove the thyroid glands, and this will regulate hormone production. This method is great, as your cat won’t need medication for the rest of its life. However, even though it’s a simple procedure, it isn’t without its risks.
  • Radioactive ions are applied in the form of iodine. This method is very effective at fighting this disease. It’s a tried and tested method in cats suffering from hyperthyroidism, and is 100% successful.

The radioactive ion treatment involves daily injections of radioactive iodine. This iodine will attack the glands, control them and won’t let them create more hormones than they should. The main advantage? In just two weeks, your cat will be completely cured. And, best of all, it won’t need surgery or lifelong medications.


Remember that it’s important to keep an eye on your pet throughout its entire life. Watch out for any change in character, because, as with hyperthyroidism, it may be a sign that something is wrong.

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