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Home > Cats > Cat Endocrine System 101: Our Vet Explains

Cat Endocrine System 101: Our Vet Explains

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Dr. Maria Zayas

Veterinarian, DVM

The information is current and up-to-date in accordance with the latest veterinarian research.

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Do you know what exactly the endocrine system is and how it works? Cat’s endocrine systems aren’t very different from people’s systems, but since most of us are taught very little about this particular bit of anatomy, it means it can be a mystery when trying to understand our cats also.

The good news is this body system isn’t all that complicated after all and performs several important functions. We’re going to go over everything you need to know about the endocrine system in cats, so you never have to wonder again.


What Is the Endocrine System?

Endocrine tissue, usually in the form of glands, are cells in the body that produce chemicals to help coordinate body functions. These chemicals communicate different messages across the body. They’re better known as hormones.

Some of the jobs of the endocrine system include the following:
  • Metabolism
  • Bone density
  • Energy level
  • Puberty
  • Pregnancy
  • Stress levels and responses
  • Blood sugars
  • Body growth
  • Hair growth
  • Body weight
  • Maintaining hydration and blood pressure


Components of the Endocrine System in Cats

The following glands and organs make up the endocrine system of cats. They are responsible for producing hormones and releasing them into the bloodstream so they can travel where they need to control different processes in the body.

  • Pituitary gland: Attached at the base of the brain, this gland is the head of the endocrine system, mostly releasing hormones that tell other parts of the endocrine system what to do.
  • Parathyroid glands: As the name implies, these paired glands rest on either side of the thyroid glands and control calcium levels and, therefore, bone density.
  • Thyroid glands: These glands produce metabolism-related hormones and help with calcium levels.
  • Adrenal glands: Sitting at the top of the kidneys, these glands have layers that control different functions. Those include stress responses, hydration and electrolyte levels, and inflammation and immune responses.
  • Pancreas: This important organ regulates blood sugar levels.
  • Ovaries: These are responsible for puberty and pregnancy in female cats.
  • Testes: The testes are responsible for puberty in male cats.


Important Endocrine Disorders of Cats

While a cat’s endocrine system works hard to keep all body systems in balance, there are a couple of diseases cats are prone to because of breakdowns within this system.

sick cat covered in blanket lies on the window in winter
Image By: Germanova Antonina, Shutterstock


Cats can develop benign tumors on their thyroid as they age, which leads to the overproduction of thyroid hormones. Signs of hyperthyroidism in cats include increased appetite, weight loss despite eating well, increased vocalizations, increased drinking, and increased urination.

A quick blood test can confirm elevated thyroid values and a veterinarian can recommend the best treatment option as there are several, including shrinking the tumor via radiation, daily thyroid hormone-blocking medication, or a specialized diet that limits the production of thyroid hormones via a selective nutrient deficiency (iodine).


Cats whose pancreas fails to make insulin or whose cells fail to respond to insulin will have high blood sugars. This is because insulin is a hormone the pancreas produces that tells cells to take up sugar from the blood to store or use for energy. This keeps the body up and functioning while also maintaining blood sugar levels within a normal range.

Diabetic cats may show lethargy, vomiting, increased drinking, urination, and decreased appetite. To treat this, cats can be given injections of additional insulin to help bring down their blood sugar levels and alter their diet to support steady blood sugar levels.



What are metabolic disorders in cats?

These are endocrine disorders, and they’re one and the same. Common examples would include diabetes and hyperthyroidism for cats.

What are the signs of endocrine dysfunction in cats?

Signs would include weight loss, increased appetite, increased drinking, increased urination, lethargy, vomiting, and/or increased vocalizations.

sick grey cat
Image By: Anna Nikonorova, Shutterstock

What kind of hormones does a cat’s endocrine system produce?

While there are many hormones in a cat’s body, some of the most important are thyroxine, insulin, estrogen/progesterone/testosterone, and cortisol.



While you may not have needed to know exactly what the endocrine system was before, hopefully, now you know everything important about your cat’s endocrine system. It is responsible for producing hormones, which in turn are responsible for controlling important body processes like metabolism, puberty, pregnancy, blood sugar levels, stress responses, and more. Cats are mostly only prone to two endocrine disorders, diabetes and hyperthyroidism, though both are relatively common in senior cats.

If you see signs of endocrine dysfunction in your cat, it is best to bring them to the vet so they can perform screening blood work to look for the cause. Both have several treatment options to help you find what’s best for you and your cat.

Featured Image Credit: Lost_in_translation, Shutterstock

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