Diabetes - Mellitus

Definition of Diabetes Mellitus

“Diabetes” is a general term used to refer to a group of complex metabolic disorders that cause excessive urination and excessive thirst/water intake. There are two distinct forms of diabetes in dogs: diabetes mellitus and diabetes insipidus. This article addresses the first of those, diabetes mellitus, which is sometimes referred to as “sugar diabetes.”

Causes of Diabetes Mellitus

Diabetes mellitus comes in two forms, called Types 1 and 2. Type 1 diabetes mellitus, or insulin-dependant diabetes, is similar to the juvenile-onset form of diabetes in children. Type 1 diabetes mellitus involves the malfunction, destruction or congenital absence of certain cells in the pancreas called islet beta cells. “Congenital” means something that is present at birth. In healthy animals, the pancreatic islet cells produce and secrete the hormone, insulin. Insulin is necessary for metabolism of carbohydrates, proteins and fats and is essential for regulating normal blood glucose levels. Put differently, insulin must be present in the right amount for glucose from ingested food to be able to enter individual body cells, where it can then be metabolized and used to produce energy. Severe cases of pancreatitis can damage the islet cells and contribute to this form of diabetes. Type 1 diabetes mellitus is the most common form of diabetes in domestic dogs. It is thought to have a strong genetic component.

Type 2 diabetes mellitus, or non-insulin-dependant diabetes, is comparable to adult-onset diabetes in people. Dogs with this form of the disease typically have normal blood insulin levels, but their cellular receptors for insulin do not work properly. As a result, the cells of the body cannot take up and process dietary sugars. Type 2 diabetes mellitus is extremely uncommon in dogs, but is the most common form of diabetes in companion cats.

Prevention of Diabetes Mellitus

There is no recognized way to prevent domestic dogs from developing either type of diabetes mellitus. This disease occurs based on a combination of developmental, genetic and environmental influences that are difficult, if not impossible, to manage and are not well-understood. Certainly, obesity should be avoided in all companion animals, and it is especially problematic in diabetic dogs. Dogs suffering from recurrent pancreatitis have an increased risk of developing diabetes mellitus, as are older, overweight intact females.

Special Notes

Diabetes mellitus probably has a strong hereditary component, as it is more common in certain breeds and families of dogs.