Feline Hyperthyroid Disease

The feline hyperthyroid disease is caused by a hormonal imbalance and is more frequent in senior cats. Hyperthyroidism is caused by an excess of thyroid hormones, which are responsible for the regulation of metabolism. If these hormones are in excess, the metabolism is sped up and all the rest of the functions are accelerated. This may result in heart, kidney or gastrointestinal problems.

Symptoms of Feline Hyperthyroid Disease

The thyroid gland is part of the endocrine system and produces the thyroid hormones.

If the amount of the produced hormones is too high, the cat will suffer from hyperthyroidism.

In rare cases, the hyperthyroid disease is a secondary disease and may be caused by tumors in the thyroid area.

Hyperthyroidism leads to a faster metabolism and accelerated body functions. Typical symptoms of hyperthyroidism include:

  • Increased appetite; the cat may eat up to twice as much as usual
  • Excessive thirst; monitor the water bowls to determine how much your cat drinks
  • More frequent urination, due to the increased amounts of water
  • Hyperactivity
  • Weight loss, due to increased metabolism
  • Vomiting
  • Diarrhea
  • Greasy coat
  • Hair loss and even bald spots
  • Acne, especially in the chin area
  • Aggressiveness; sudden changes is behavior

The thyroid glands are enlarged and the cat may also experience heart murmur, high blood pressure, kidney and intestinal problems.

These symptoms may point to kidney or liver disease and even cancer, so the vet needs to run some tests to make sure your cat suffers from hyperthyroidism.

Treatment of Hyperthyroidism

If detected in timely manner, hyperthyroidism may be kept under control with medication.

The purpose of the medication is to reduce the production of thyroid hormones. Methimazole drugs are typically prescribed to cats with hyperthyroidism. Methimazole can be administered twice per day. In rare cases, there may be side effects such as lack of appetite, vomiting, sleepiness, scratching or bleeding. If you notice any of these side effects talk to your vet, as the drug might have to be discontinued.

However, the medication cannot fully treat the condition; surgery or radioiodine therapy is necessary.

Surgery, also known as thyroidectomy will treat the condition; thyroid tissues are removed and the hormonal balance is re-established. In some cases, both thyroid glands will be removed entirely to prevent the hyperfunction. The cat must get calcium supplements post surgery.

Radioiodine therapy is also successful in treating the condition. The radioactive iodine therapy consists of radiations that will destroy the thyroid tissues that are hyperactive. The rest of the thyroid tissues will function normally after the therapy is discontinued. Radioiodine therapy side effects are very rare or inexistent.

It is important that the cat is monitored by the vet for the first months during the treatment to make sure the results are positive.

Hyperthyroidism is not a preventable disease. However, the disease may be cured, if it is detected in time and it is not a secondary disease caused by cancer or tumors.