So often do I hear from my clients, “Dogs and cats can get diabetes too?!” The simple answer is yes.

Diabetes, or diabetes mellitus, in animals is a disease of the pancreas that results in the lack of production of the hormone insulin. This very important hormone is required to allow the absorption of glucose (sugar) from the bloodstream into the cells of the body. Glucose, which comes from our pet’s diets, is used by the cells for food. Insulin is like a key that unlocks the door to separate cells from the sugars in our bloodstream. The body cannot detect the glucose in the blood and is fooled into thinking it is starving. As a result, the body searches for alternate energy sources such as fat and protein. The byproducts of fat and protein metabolism can create an excess of ketones.

Meanwhile, in the diabetic patient, the blood stream continues to carry excess amounts of glucose. These high levels of glucose in the blood overwhelm the kidneys, which normally function to conserve glucose, and now spills into the urine and is lost. To the kidneys, glucose acts as an osmotic diuretic, drawing water with it into the urine. This leads to excess urine production and in turn excess thirst to keep up with the fluid loss.

Signs of Diabetes

Now that we understand how diabetes works, how can we recognize that our pet may have diabetes? The most common clinical signs include increased urination (often with urinary accidents in the house) and thirst, excessive appetite and weight loss (remember the body of a diabetic pet feels as though it is starving). Diabetic dogs can also develop cataracts, so vision loss is often noted.

When pets develop these symptoms, concerned pet owners often come to see me. A diagnosis of diabetes can be made from a physical exam and lab work. A diabetic pet will have persistent high blood glucose and will have excess glucose on an examination of a urine sample.


Successful treatment of diabetes in dogs and cats involves long acting insulin therapy along with dietary management and regular exercise. Your veterinarian will decide which insulin will be appropriate to use, and how to store, handle, and administer it. In terms of diet, diabetic cats respond best to low carbohydrate, high protein choices. Diabetic dogs, alternatively, respond best to high fiber diets. At home monitoring of clinical signs (i.e. presence of excessive thirst and urination, stabilizing weight) and periodic physical exams and lab work monitoring by your veterinarian are vital to the success of treatment.

Blood glucose monitoring (whether in the veterinary clinic or at home) help tell us how the pet’s blood sugar is responding to the dose of insulin chosen and whether or not adjustments need to be made. Diligent monitoring can help key in on complicating factors that can affect successful treatment. Periodic urinalyses are used to screen for urinary tract infections or diabetic acidosis. Routine dentistry at your local vet is also important, because dental and periodontal disease can affect how well regulated a diabetic can be.

A significant, potentially life threatening result of uncontrolled diabetes mellitus is diabetic ketoacidosis. This occurs when the body remains in the starvation state long enough that the metabolic byproducts of protein and fat accumulate in toxic amounts. As a result, pH and electrolyte imbalances occur, often leading to shock and dehydration. These severely ill patients will most likely need intensive, in-hospital care.

Diabetes mellitus is very much a preventable disease. The most common risk factor is persistent obesity. The keys to preventing obesity are maintaining proper caloric intake, avoiding table scraps and regular exercise. If you believe your pet to be obese or over weight, contact your veterinarian to help initiate a weight loss regimen. –Peter Olson, DVM

Peter Olson, DVM, is a 2007 graduate of The Ohio State University School of Veterinary Medicine. He and his wife Beth share their home with two dogs, two cats, four turtles and a Russian Tortoise.