When you are looking at cat health, hyperthyroidism is among the most common diseases seen in older cats. In case your feline friend continues to be diagnosed, learn what hyperthyroidism in cats is, why it happens as well as your treatments.

What Is Hyperthyroidism in Cats?

Just like people, cats have a thyroid situated in their neck where it secretes hormones that regulate the cat's metabolism. The primary hormones secreted by the thyroid gland are T3 and T4. The thyroid gland creates these hormones with iodine obtained from the bloodstream, and also the metabolism of each and every other cell in your body is dependent upon thyroid hormones.

If thyroid hormone is low, then the metabolism is low. When the thyroid hormone is high, then metabolism is high. A cat with an overactive thyroid secretes too much thyroid hormone in to the blood stream, hyping up every other system in the body. This is an good way to remember hyperthyroidism-it helps make the body too hyper!

Symptoms of Hyperthyroidism in Cats?

Hyperthyroidism causes very distinct alterations in the body and behavior of the cat. Included in this are:

  • Oodles of energy
  • More talkative or vocal
  • Increased appetite
  • Thirstier than normal
  • Vomiting
  • Diarrhea
  • Hair loss, especially around the ears and forehead
  • Excessive scratching or grooming
  • High blood pressure
  • Increased heart rate
  • Retinal detachment because of hypertension popping off the retinas. (Retinal detachment causes acute blindness with dilated pupils.)

What Causes Hyperthyroidism in Cats?

Hyperthyroidism is really a disease seen in older cats in most cases is brought on by the growth of a benign tumor called an adenoma on the thyroid. Rarely, these tumors could be malignant. The cause of the tumor remains unknown, but theories include diet or chronic exposure to chemicals.

How is Hyperthyroidism in Cats Diagnosed?

Hyperthyroidism is afflicted with a mix of a veterinary physical examination and laboratory testing. During the physical exam, your veterinarian also might measure blood pressure level.

If the vet suspects hyperthyroidism, a blood and urine sample out of your cat is going to be listed in the lab for testing. Several tests may be ordered, such as T4, free T4 and TSH. Your veterinarian also might order an entire blood count, blood chemistry and urinalysis. Hyperthyroidism is diagnosed by finding abnormalities during these tests.

How Is Hyperthyroidism in Cats Treated?

Hyperthyroidism shortens the quality and quantity of your cat's life and really should be treated if diagnosed. There are many possibilities to treat hyperthyroidism in cats.

Thyroid Medication for Cats

Methamizole is a medication accustomed to treat hyperthyroidism. Medicines does not cure hyperthyroidism, but it does reduce the amount of thyroid hormone released.

It typically is administered twice daily for life. If you discontinue the medication, the symptoms of hyperthyroidism will return. Some cats experience gloomy effects, most commonly vomiting and diarrhea.

Cats on this kind of therapy typically need blood and urine tests twice a year to watch thyroid hormone levels and kidney function. Methamizole usually is prescribed as a pill; however, it may be formulated into a cream to rub to your cat's ear if pilling your cat daily isn't something you think you are able to or want to do.


Surgical therapy for hyperthyroidism in cats consists of surgically removing the thyroid that has the tumor present. This effectively cures the disease and is a great choice for cats with malignant tumors and for clients who don't want to give their cats medication.

Risks include death during surgery, hypoparathyroidism (low blood calcium) and recurrent hyperthyroidism if your tumor grows on the other gland.


Dietary therapy involves switching the kitty to a prescription diet formulated to reduce thyroid hormone production and support urinary, kidney and heart health. One option is Hill's Prescription Diet y/d thyroid care dry cat food. It's been proven to clinically help some hyperthyroid cats within 3 weeks of starting the diet.

Radioactive Iodine Treatment

Radioactive iodine treatment is considered the very best therapy choice. In this treatment, radioactive iodine is injected in to the bloodstream. A thyroid problem gland occupies the radioactive iodine and also the iodine selectively kills abnormal thyroid tissue.

Most cats have normal thyroid hormonal levels 10-14 days after treatment. Cats remain hospitalized for 3-5 days after treatment to avoid exposing people to radiation.

The incidence of negative effects is extremely low. In rare cases the therapy should be repeated, as well as in even rarer cases the cat becomes hypothyroid (the alternative of hyper) and a thyroid supplement is required.

Talk with your veterinarian about these options and decide together what is the best option for you as well as your cat.