Hyperthyroidism in Cats

What is Hyperthyroidism?

The thyroid gland in the neck, produces the hormone thyroxine, which regulates lots of processes in the body.

When the thyroid gland produces too much hormone, cats can get very poorly, very quickly.

Their bodies use up the energy from food too fast, meaning that they lose weight, whilst having a good or really good appetite.

If untreated, it can cause high blood pressure, heart failure and death


The main signs of an overactive thyroid gland are:

  • Weight Loss

  • Increased Appetite 

  • Increased Drinking/Thirst

  • Increased Activity

  • Restlessness

  • Unkempt/dishevelled looking coat

  • Increased Heart Rate


We diagnose hyperthyroidism by:

  • Physically examining your cat

  • Asking you questions about their recent behaviour

  • Blood tests to measure various components in the blood


After confirming an overactive thyroid gland, we discuss the best treatment options for your individual cat

This treatment might be:

  • Tablets

  • Surgery

  • Specialist Radioactive Iodine Treatment

  • A Special Diet 

Hyperthyroidism in Dogs

An overactive thyroid gland is very uncommon in dogs.

Dogs usually suffer from an underactive thyroid gland