The Cat Hospital

137 E. Hamilton Ave.
Campbell, CA 95008


Feline Diabetes Mellitus


Feline Diabetes Mellitus is a hormonal disease affecting approximately 1 in 300 adult cats. The condition can occur in any cat but is statistically more common in older, obese male cats. Diabetes mellitus can be a complex problem; however, in nearly all cases the issue is that the cat either doesn't have enough insulin or the body can't properly use the insulin it does produce.

Insulin is a hormone produced in the pancreas, which is located in the abdomen near the stomach and first segment of the small intestine. Insulin is responsible for regulating the flow of glucose from the bloodstream into the cells of the body. Glucose is a byproduct of food digestion and provides fuel to cells thus sustaining life. When insulin is deficient or the body is unable to utilize the insulin, glucose can't be used for energy. Instead, the cat's body breaks down proteins and fats. This causes the cat to eat more yet lose weight. The build up of glucose in the blood stream and increased glucose in the urine results in thirst and frequent urination. This leads to the textbook clinical signs that owners often report:

  • Increased thirst
  • Increased urination
  • Increased appetite
  • Increased weight loss

Feline Diabetes Mellitus is diagnosed based on the clinical signs, laboratory tests revealing persistently high blood and urine glucose levels, and other physical exam findings. Without treatment, most cats will become seriously ill due to electrolyte imbalance and resulting organ failure.

Treatment for Feline Diabetes Mellitus depends on the specifics of each case but the basic treatment protocol may include:

Oral hypoglycemic agents: This is not oral insulin! This drug allows the body to more effectively utilize the insulin that the cat's pancreas is still producing. If the pancreas is not able to produce insulin, oral hypoglycemic agents will not be an effective treatment.

Diet: It has been shown that a low carbohydrate/ high protein diet can dramatically reduce the amount of insulin required and in many cases eliminate the need for insulin injections entirely. There are several prescription diets that have proved to be effective. Remember that a dietary change in the cat can be challenging and in most cases needs to be gradual.

Insulin injections: These are necessary for cats that appear to be insulin dependent, meaning that the pancreas has no insulin producing capability. Giving your cat an injection can be an intimidating prospect but the reality is that in most cases it can be mastered with minimal training. In fact some cats over time prove to be non-insulin dependent and the insulin injections can be discontinued. These cats are classified as transient diabetics.

Once a cat is diagnosed with diabetes mellitus and treated, there is an ongoing monitoring protocol that must be designed. Most cats treated at The Cat Hospital are initially stabilized with intermittent blood glucose checks at the hospital. Once the blood glucose levels are stable and the insulin dose established, periodic blood glucose checks are performed at the hospital. Some owners find they are able to perform the blood glucose checks at home. This procedure is not for everyone or every cat! There are two excellent web sites that demonstrate the procedure for at-home blood glucose checks:

Home Testing of Blood Glucose for Diabetic Cats  and

The Cornell Feline Health Center is also an excellent source of information about diabetes and other feline health topics, and can be found at

While Feline Diabetes Mellitus is a treatable disease, it can also be a complicated condition and regulation of the blood sugar challenging. At times the treatment course can be frustrating and expensive. The staff at The Cat Hospital will try to mitigate any difficulty by providing you with the information you need to maximize the treatment effort.