November is Diabetes Awareness Month in both animal and human medicine. Diabetes mellitus, sometimes called “sugar diabetes” caused by disease in the insulin-producing cells of the pancreas. Insulin is a hormone that regulates the levels of glucose or sugar in the body. Glucose is a vital substance that provides much of the energy needed by cells, and it must work inside the cells. Insulin attaches to ‘receptors’ on the surface of body cells and opens “pores” through the cell wall that allow glucose to leave the bloodstream and enter the cell’s interior.  Without an adequate amount of insulin to “open the door,” glucose is unable to get into the cells, and accumulates in the blood. In simple terms, the symptoms that we see in patients with diabetes mellitus are caused by a deficiency of insulin. 

There are two main types of diabetes mellitus. Both types are similar in that there is a failure to regulate blood sugar, but they differ in their cause and treatment. With Type I Diabetes Mellitus (also called Insulin Dependent Diabetes Mellitus) the insulin-producing cells are either destroyed or become non-functional, causing an absolute deficiency of insulin in the body. This is the most common type of diabetes in dogs, but is relatively rare in cats.  

With Type II Diabetes Mellitus, insulin is still produced by the pancreas, but either too little is produced, too little is released, or the tissues of the body do not respond properly to it. This is the most common type of diabetes in cats. Obesity is a predisposing factor for Type II diabetes in cats, dogs and humans. People with this form of diabetes may respond to treatment with oral medications that stimulate the production or release of insulin. Unfortunately, dogs rarely respond to this form of medication and only a small proportion of cats are helped by it.

The four main symptoms of uncomplicated diabetes mellitus are increased thirst, increased urination, weight loss and increased appetite. These symptoms are directly related to the high concentration of glucose in the bloodstream and/or the inability of the body to use glucose as an energy source. The onset of symptoms may be gradual, and in its early stages these signs may go unnoticed in dogs and cats.

Diabetes mellitus is diagnosed by means of blood and urine tests; in some cases a short stay in the veterinary hospital may be necessary to diagnose the disease and start the treatment.

The majority of cats and dogs with diabetes mellitus require insulin injections as part of the treatment for their disease. Nutrition is a key component of the treatment of diabetes mellitus and the appropriate diet modification may lower the pet’s requirement for insulin. Many cats with this disease appear to benefit from a diet that is high in protein and low in carbohydrates.  By contrast, diabetes mellitus has shown to be a ‘fibre-responsive disease’ in dogs, and addition of the appropriate form of fibre to the diet improves the success of treatment. Once treatment has begun, controlled weight loss is beneficial in obese pets of either species.

The incidence of diabetes mellitus is increasing at an alarming rate, due in part to the tremendous increase in obesity. It is important that we, as pet owners, become awareness of the disease and the role that obesity plays in its development so that we can do our part in preventing this potentially fatal and costly disease from afflicting our furry friends.