What is Hyperthyroidism?

Hyperthyroidism is when there is an increase in the production of thyroid hormones. This increase in thyroid hormones can cause hyperthyroidism.

How Does This Happen?

Most of the time the cause is a benign tumor called adenoma. Sometimes, a cancerous tumor called adenosarcoma may be the cause of hyperthyroidism. Both will create a lump that can easily be seen and felt.

What are the Symptoms?

Thyroid hormones directly affect most of the cat’s bodily organs and overall pet health, the signs can be different depending on if there are pre-existing health conditions. The initial signs may be subtle and as the disease progresses, they can show them as more severe.

• Your cat will have a good appetite but is losing weight.
• Drinking more water than usual.
• Urinating more than usual.
• Your cat may look like they are not well groomed.
• Your cat may vomit.
• Your cat may have diarrhea.

Other health conditions can cause the same symptoms, so it is best to get your cat checked by your veterinarian.

How is Hyperthyroidism Treated?

• A physical exam will need to be done to detect any thyroid enlargement.
• Blood and urine tests will probably be required.
• Blood and urine tests can also detect any other health conditions that may be present.
• Treatment is so important otherwise the condition will get worse and affect your cat’s quality of life and lifespan.

What is the Treatment?

• Anti-thyroid drugs reduce the production and release of thyroid hormone. This medication can help control symptoms, but they are not a cure.
• Surgery to remove part of the thyroid gland. If all the diseased tissue is removed then surgery, in many cases, results in a cure.
• Radioactive Iodine Therapy involves injecting radioactive iodine. The radioactive iodine is taken up by the thyroid gland. The iodine destroys the tumor cells without damaging the normal cells. Your cat will return to normal production of thyroid hormones in a few weeks.
• Limiting the amount of iodine ingested through diet can help to control hyperthyroidism in your cat. Typically, by feeding a veterinary diet.
• If diet is the desired treatment over surgery or Iodine Therapy, then your cat can eat nothing else but this food.
• If your home has multiple cats, then the other cats cannot eat the prescription diet, as it may have lower than usual iodine levels.