Treating hyperthyroidism

Since very few cats with hyperthyroidism have cancerous growths of the thyroid gland, treatment is usually very successful. The treatment’s purpose is to bring the amount of thyroid hormone in the cat’s blood back to normal. This can be achieved in 3 ways:

1. Medical treatment – medication is given every day to reduce the production of thyroid hormones. Medication can be used for short-term or long-term treatment.
2. Surgical treatment – an operation is performed to remove the abnormal thyroid tissue.
3. Radioactive iodine therapy – the abnormal thyroid tissue is destroyed by radioactive treatment. A cat treated in this way needs to go to a special treatment centre and remain there for several weeks.

Most cases of hyperthyroidism are initially treated with daily anti-thyroid medication for 3 weeks to return thyroid hormone levels in the blood back to normal. Once this is achieved the cat’s response to therapy can be assessed before making a long-term treatment decision.  The risks of any anaesthesia and surgery are also greatly reduced.