You might wonder what hyperthyroidism means for your cat if it has been diagnosed.

What is hyperthyroidism and how can it be treated?

Hyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone due to abnormal functioning. It is most commonly seen in older cats and is the most common form of endocrine disorder. Both male and female cats can get it. The incidence of the disease is higher in Siamese cats than other breeds.

• Hyperthyroidism in cats: Causes and symptoms

Hyperplasia, which refers to an excess of thyroid tissue, is the most common cause of thyroid abnormalities. Thyroxin is a hormone produced by the thyroid. Thyroxin is broken down to a form that the body can use to regulate heat production and metabolize fats, proteins, and carbohydrates. Overproduction of thyroxin can lead to problems such as excessive thirst, hunger, and weight loss despite eating large quantities of food. Another issue that could arise is a poor hair, vomiting, diarrhea and weakness. Hyperactivity can also occur, which often results in the cat becoming vocal and unable to settle.

Hyperthyroidism may also cause symptoms that aren’t obvious, but can lead to serious health problems. For example, cardiomyopathy is a type of heart disease where the muscles become thickened. The heart must work harder to pump blood. This can lead to thickening of the heart chambers. Hypertension, or high blood pressure, is a result of increased heart activity. If left unchecked it can cause retinal bleeding and detached retinas that can lead to blindness.

• Hyperthyroidism Treatments

Hyperthyroidism can be treated. Once the hormone levels are stable, it is possible to reverse the effects of an overactive thyroid. Methimazole is the most commonly used anti-thyroid medication. You can give it as a tablet, a liquid, or transdermally by placing a gel on your cat’s ears. Methimazole is essential for cats to be given the right daily dose. Your veterinarian will help you monitor your cat’s blood work and prescribe the appropriate dosage.

There are also other options. I-131 radiation therapy is one option. This uses radioactive iodine to destroy thyroid tissue and not affect surrounding tissues. This non-invasive treatment can be done at a specialist clinic and is not required to treat hyperthyroidism. The surgical removal of the thyroid tissue is another option. Thyroid medication is no longer required after this procedure. Your veterinarian can provide information about clinics that offer these services in your local area.

In some cases, a restricted diet containing iodine can prove to be beneficial. Excessive levels of iodine found in cat food may lead to hyperthyroidism. Therefore, feeding your cat a diet with low levels can help to normalize thyroid function without needing to give daily medication. Although this may seem the easiest option, it can be difficult to feed a cat a diet that is iodine-restricted. Your cat must only eat this diet for the rest her life. This means that you can’t give your cat treats and you must not allow her to eat any other cats’ food if you have multiple cats. Regular monitoring of thyroid levels via blood work is essential for any of these treatments.

How to treat feline thyroid disease?

You should consider the cost of treatment as well as convenience and how your cat will be treated. Methimazole can be administered daily to cats. However, if your cat is allergic to the medication, it may be necessary to switch to another treatment. While surgery and I-131 radiation therapy are expensive initially, once they’re done you will only need to continue blood-work monitoring. If you are able to ensure that your cat is eating the right food, an iodine restricted diet may be a viable non-invasive option.

The clinical signs usually reverse once effective treatment is given and maintained. Your cat can then live a normal life. The clinical signs and health problems described above will continue to worsen without treatment. Once hyperthyroidism is diagnosed, it’s in your best interests to treat your cat. Your veterinarian will help you determine the best treatment for your particular situation.