Hyperthyroidism in Cats (Overactive Thyroid): Symptoms and Treatment

According to data, 10% of cats over ten years of age suffer from hyperthyroidism. Thankfully, these cats can live a long and quality life if their condition is managed with treatment. However, untreated hyperthyroidism in cats may lead to heart failure, digestive system diseases, and death.

What Is Hyperthyroidism in Cats?

Hyperthyroidism in cats is when the thyroid gland produces too much of the hormone thyroxine.

This can happen for a variety of reasons, such as:

  • A benign tumor on the thyroid gland
  • An overactive pituitary gland
  • Congenital defects
  • Inflammation of the thyroid gland

Cats typically have two thyroid glands on each side of their neck. In hyperthyroidism, one or both of these glands produce too much thyroxine. Thyroxine is responsible for regulating the body’s metabolism.

When there is too much thyroxine in the body, it causes the metabolism to speed up. This can then stress the heart, digestive system, and other organs in their body.

Signs and Symptoms of Hyperthyroidism in Cats

The most common signs and symptoms of hyperthyroidism in cats are:

  • Weight loss
  • Increased appetite
  • Hyperactivity
  • Restlessness
  • Excessive thirst and urination
  • Other less common signs of hyperthyroidism in cats include:
  • Vomiting
  • Diarrhea
  • Constipation
  • Panting
  • Coat changes (thin, brittle fur)
  • Muscle weakness
  • Lethargy
  • Heart murmur

Diagnosis of Hyperthyroidism in Cats

You should take your pet to a clinic or hospital for a proper diagnosis of hyperthyroidism in cats.

Several tests can be done to diagnose hyperthyroidism, including:

  • Blood tests – these can measure the level of thyroxine in the blood and may also check for kidney function.
  • Imaging tests – such as x-rays or ultrasounds – can help to assess the size of the thyroid gland(s).
  • Thyroid scan – this uses radioactive iodine to look at how well the thyroid gland is working.

Choosing a vet clinic or hospital is crucial for diagnosing and treating hyperthyroidism in cats. Make sure to select a facility with experience in treating this condition, complete equipment specialists, and diagnostic tests, such as cat and dog chest x ray, blood tests, ultrasound, etc.

How Is Hyperthyroidism Treated in Cats?

1. Radioactive Iodine Therapy

Vets often recommend radioactive iodine therapy for feline hyperthyroidism. This therapy involves a dose of radioactive iodine to destroy the overactive thyroid gland(s) cells.

This therapy offers a cure for hyperthyroidism in the vast majority of cases. It is also relatively safe and has very few side effects.

The downside to this therapy is that it requires your cat to stay at the hospital for several days while receiving the treatment. Additionally, this therapy is not always available, as it requires special licensing. Learn more about this treatment by visiting this page.

2. Surgery

Surgery is another option for treating feline hyperthyroidism. This involves the removal of the overactive thyroid gland(s).

This treatment is often recommended for cats not good candidates for radioactive iodine therapy. It is also recommended for cats that have tumors on their thyroid glands.

The downside to this treatment is that it carries a higher risk of complications, such as bleeding or infection. Additionally, your cat will need to stay at the hospital for several days after the surgery.

3. Anti-Thyroid Medication

Anti-thyroid medication can be used to treat feline hyperthyroidism. It works by blocking the production of thyroxine in the thyroid gland(s).

The downside to this treatment is that it must be given twice a day for the rest of your cat’s life. Additionally, this medication can have side effects, such as vomiting and diarrhea.

4. Dietary Change

A dietary change is often recommended for cats with hyperthyroidism. This diet consists of foods low in iodine, such as certain types of canned tuna.

The downside to this treatment is that it may not be effective in all cases, and it can be hard to find the suitable food for your cat. Additionally, this diet may not be palatable for some cats.

Monitoring Your Cat’s Hyperthyroidism

Once your cat has been diagnosed with hyperthyroidism, it’s important to monitor their condition closely. This typically involves regular check-ups with your vet and periodic blood tests to check thyroxine levels.

Your vet will also likely recommend lifestyle changes for your cat, such as switching to a diet low in iodine. Additionally, you should keep an eye on your cat’s weight and appetite, as well as their energy levels and general health.

Preventing Hyperthyroidism in Cats

There is no sure way to prevent hyperthyroidism in cats. However, there are a few things you can do to reduce your cat’s risk:

  • Feed them a balanced diet – this will help ensure they get the proper nutrients, including iodine.
  • Avoid feeding them table scraps – this can increase their risk of obesity, a risk factor for hyperthyroidism.
  • Don’t smoke around them – secondhand smoke increases the risk of hyperthyroidism in cats.
  • Keep them up-to-date on their vaccinations – this can help reduce their risk of infection, a possible trigger for hyperthyroidism.

Talk to your vet about any concerns you have – they may be able to offer additional advice on preventing hyperthyroidism in your cat, such as performing pet X-ray in case of goiter. Or, if your cat is already showing signs of hyperthyroidism, they can perform an ultrasound to check for thyroid tumors.