Hyperthyroidism (High Blood Thyroxine)

Hyperthyroidism is a debilitating illness of middle aged and older cats.

Symptoms can include any or all of the following:

  • Weight loss
  • Excessive thirst
  • Vomiting and diarrhoea
  • Hair loss
  • Heart murmur
  • Irritable mood
  • Hyperexcitability

It is caused by a benign tumour in the thyroid glands in the throat.

When your vet suspects the condition is present, a simple blood test is all it takes for a diagnosis.

The condition can be treated very successfully and full resolution of symptoms can be achieved.
The most convenient and safest treatment is daily medication with tablets. Importantly, this is not a cure but will suppress thyroid production enough to be just as good. Most cats and their owners avail of this treatment as success rates are usually excellent.

However, not all cats will readily take medication- so the other option is surgery.Surgery can be curative but is not without particular risks in this case, which would need to be discussed and evaluated in collaboration with the vet.

Finally, the gold standard treatment for hyperthyroidism is treatment with radioactive iodine. Whilst not invasive or painful for the patient, this option requires cats to be isolated for up to two weeks following treatment, as there is a public health risk from their bodily fluids following treatment. Unfortunately, this treatment is not yet available in Ireland, so pets receiving this treatment need to travel abroad.


What Needs to be done?

If your cat is displaying any of these symptoms, please phone the clinic for advice!