Diabetes in Cats

Updated: 4/8/24
An obese cat


Diabetes mellitus (diabetes) is a chronic condition that affects a cat’s endocrine (hormone) system. Diabetes occurs when a cat’s pancreas cannot produce enough of the hormone insulin to process glucose (sugar). Sugar then builds up in the bloodstream and can’t be used by the body for energy.

There is no cure for diabetes in cats, but it can be managed successfully.

Risk Factors

Diabetes often affects overweight, older male cats. Obesity is a common cause of insulin resistance, where the body produces normal amounts of insulin, but the insulin doesn’t work appropriately within the body.

Cats treated with steroids or other immunosuppressive medications are also predisposed to diabetes, since these drugs can cause insulin resistance.


Signs of diabetes include:

  • Weight loss despite increased appetite
  • Increased urination
  • Increased thirst


It can be difficult to diagnose diabetes in cats since they often have a high blood sugar level when they are stressed by a visit to the veterinarian.

A diagnosis is made based on clinical signs reported by the owner, a high blood sugar level, and sugar in the urine.

A fructosamine test, which is a blood test that measures the sugar levels for the previous two weeks, may also be used.


Cats typically need twice daily doses of insulin either through injections or an insulin pen. You will need to give an insulin shot every 12 hours, but the injections are painless, fast, and easy to give.

Veterinarians typically depend on clinical signs reported by owners to see if diabetes is being managed properly. It may be helpful to keep a log of how often your cat urinates, how much water she drinks, her appetite, and the insulin dose. You might also use tools such as urine dipsticks to measure the amount of sugar in the urine and at-home blood sugar tests.

You may be able to check your cat’s blood sugar using a portable glucometer. This involves pricking the ear for blood at specific times after insulin administration. Be sure to follow your veterinarian’s instructions when adjusting the insulin dose to avoid giving too much or too little.

If diabetes is treated early, cats may experience an insulin remission, where they no longer need daily injections. However, it’s hard to predict when, if, or how long remission will last.


The best way to prevent diabetes from developing is to feed your cat a nutritious diet and to keep her at a healthy weight.

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