Treatment Options for Hyperthyroidism

Hyperthyroidism Treatment for Cats | Medication, Surgery & Radioiodine

Compare treatment options for hyperthyroidism in cats, including medication, diet, surgery and radioiodine (I-131). Find the best option for your cat.

Choosing the right treatment

There are several ways to treat hyperthyroidism in cats, each with advantages and limitations. The right choice depends on your cat’s health, temperament, and your preferences as an owner. There are four options available, two of these provide a cure to the disease, and two of these offer lifelong management of the disease.

Management

Medical treatment is often recommended. Tablets, liquids, or gels applied to the skin can control thyroid hormone production and stabilise the condition. However, this approach does not cure the disease and requires lifelong daily treatment, along with regular blood tests (every 3 months, for life). The disease can get worse despite treatment and the thyroid can become cancerous.

A dietary approach using a low-iodine prescription food (Hill’s y/d prescription diet) can also help control thyroid levels. This can be effective, but only if the diet is followed strictly, which is not always practical in multi-cat households or for cats that go outdoors. The cat cannot eat anything else apart from this diet, and if your cat stops eating this food then the thyroid levels will increase.

Cure

Surgery to remove either both or one thyroid gland can offer a permanent solution, but it involves general anaesthesia and carries some risk, particularly as these cats are older patients that often have other underlying diseases. There is a risk of recurrence of hyperthyroidism if only one thyroid gland is removed. Surgery is generally cheaper than treatment with radioiodine.

Radioiodine treatment (I-131)

Radioiodine therapy is widely regarded as the most effective and definitive treatment for feline hyperthyroidism. It involves a single injection of radioactive iodine that selectively destroys abnormal thyroid tissue while leaving healthy tissue largely unaffected.

Unlike surgery, it treats all thyroid tissue, including areas that cannot be reached surgically. Most cats require only one treatment and do not need ongoing medication afterwards.

Helpful Links

International Cat Care – Hyperthyroidism in cats