Mimi Noonan, DVM, DACVIM

Diabetes is a common hormonal problem of dogs and occurs when there is either a deficiency of insulin or cellular resistance to its effects. Dogs with diabetes most commonly come to the veterinarian because they are losing weight, drinking excessive amounts of water and urinating more frequently, sometimes breaking housetraining.

Just like with humans, dogs can have different types of diabetes. The majority of diabetic dogs have Type I diabetes and are insulin dependent for life. A small percentage of dogs develop diabetes secondary to their own hormones, a chronic medication or inflammation of the pancreas. Therapy for the hormonal problem, withdrawal of the offending medication or resolution of the pancreatic inflammation sometimes results in remission of the diabetic state.

Insulin dependent dogs enjoy a good quality of life and long survival with collaboration with a veterinarian and consistent commitment to care at home. Insulin injections are given twice daily along with morning and evening meals and periodic monitoring of blood sugar helps determine a safe dose. Most dogs do best when fed a lower carbohydrate, higher protein prescription diet specific for the condition.

A common complication of diabetes in dogs is the development of cataracts. This happens because the excess sugar in the eye converts to sorbitol, which damages the lens. Research to prevent this is ongoing but at this time, surgical removal of the cataract by a veterinary ophthalmologist is necessary to restore full vision.

Diabetic control in dogs is aimed at reducing glucose fluctuations and minimizing the risk of long-term complications. Development of cataracts is sometimes slowed by good regulation, but 80% of diabetic dogs develop them eventually. Tight regulation, a goal for human diabetics, carries the risk of a dangerously low blood sugar; if unrecognized, a low blood sugar can cause a seizure. Well-regulated dogs may have higher than normal blood sugar, but good energy, healthy body weight and normal appetite for food and water.

Diabetic monitoring at home is available to families undeterred by the prospect of testing their dog’s blood. Dogs with a cooperative demeanor usually adapt to blood draws easily, and home testing has been shown to be significantly more accurate than in-hospital glucose testing. Implantable short-term monitoring systems commonly used for diabetic people are gaining favor for use with some challenging diabetic dogs.

Mimi Noonan is an Internal Medicine Specialist at Veterinary Specialty Center.