Diabetes mellitus occurs fairly frequently in dogs. As with humans, canine diabetes can be either Type I (insulin-dependent diabetes mellitus) or Type II (non-insulin-dependent diabetes mellitus). Type I is more prevalent, accounting for 70 to 80 per cent of cases. Type II nearly always develops in overweight or obese dogs.

Either overweight or underweight dogs can be suspected of diabetes. Dogs suffering from undiagnosed Type I diabetes will lose weight even if they are eating far more than their usual ration. Overweight dogs are more at risk for developing Type II diabetes.
Owners should also be on the lookout for increased thirst and more-frequent urination. Dogs with diabetes may be lethargic, and the condition of their haircoat will suffer.

With Type I diabetes, insulin injections will always be required, but changes in diet can help keep blood glucose levels on a more even keel. Because dogs with Type I diabetes have likely lost weight before diagnosis, they may start out on a low-fibre diet to help them gain back weight, then switch to a higher-fibre diet for better blood glucose control.

For dogs with Type II diabetes, a weight-loss program will be an integral part of treatment. Insulin injections may be needed at the start of treatment, but will likely be phased out as the dog reaches a more optimal weight and is more able to self-regulate blood glucose levels.
In either case, careful continued monitoring is required to keep diabetic dogs healthy, and to continue providing the correct nutrition.

Protein is crucial to good nutritional balance. Excess amounts could lead to renal damage, yet enough must be consumed to offset any inefficiencies in digestion and utilization. As a general guide, protein should comprise 15 to 25 per cent of calories; digestibility should be at least 85 per cent.

Simple carbohydrates are rapidly digested and cause spikes in blood glucose levels, so should be avoided. Complex carbohydrates must first be broken down into simple carbohydrates before they can be absorbed, so they retard the flow of glucose into the bloodstream. They also slow the digestion and absorption of other nutrients, again helping to regularize blood glucose. The recommendation for a diabetic diet includes 50- to 55-per-cent carbohydrates.

Diabetic dogs have an impaired ability to metabolize fat and, as a consequence, have a greater propensity to also suffer from pancreatitis. So fats must be carefully regulated, providing less than 20 per cent of the calories in the diet.

Fibre can help with control of blood glucose levels by slowing digestion. Research has found more unwanted side effects with soluble fibre (including a brittle hair coat, diarrhea, and some potential for harm to the gastrointestinal tract), so fibre should be insoluble or a mixture of insoluble and soluble. Insoluble fibres include beet pulp, corn bran, rice bran, wheat bran, peanut hulls, soy hulls and wheat middlings.

Vitamins and minerals may be depleted while diabetes is uncontrolled, but should return to normal levels once control is established.

Keeping these considerations in mind, the nutrient levels shown on the dog food label should fall within the following ranges:

Diabetic dogs also suffering from renal failure should keep to the lower end of the protein range.

Prescription diets, in both canned and dried form, are available from such pet food manufacturers as Waltham/Pedigree, Nestlé/Purina, Iams and Hill’s. Your veterinarian will likely recommend a specific brand, but because these foods are less palatable than regular off-the-shelf foods and some dogs refuse to eat them, you should be aware that other options are available if the recommended food doesn’t work for your dog.

Caring for a diabetic dog requires dedication. Several small meals at regular intervals help avoid fluctuations in blood glucose. At least two main meals should be fed, eight to 10 hours apart. A smaller meal midway between the two meals can improve blood glucose control. For particularly hard-to-control cases, four small meals a day may be necessary.

If the dog is receiving insulin injections, they must be coordinated with the meals. It works best to first have the dog eat, then give the injection immediately afterward. Reversing the order – injection first, then feeding – leaves open the possibility of insulin-induced hypoglycemia if the dog should refuse to eat for some reason. If two injections are given daily – a normal treatment plan – they should be given with the two main meals. The injections are given subcutaneously, and can easily be mastered by most owners.

With the popularity of rewards-based training, some consideration must be given to treats for the diabetic dog. The simplest option is to use part of the dog’s regular diet, but some dogs may not find that rewarding enough to work for. Owners should discuss potential treats with their veterinarian.

To keep blood glucose levels as stable as possible, training should occur at approximately the same time every day, and using the same amount of treats. Other exercise should also be kept as regular as possible.

Diabetes is an ever-changing disease, responding to changes in body weight, activity level and food consumption. Owners must remain vigilant.

Once treatment begins, water consumption and urination should decrease to normal levels. As blood glucose levels come under control, the dog can utilize nutrients more effectively, and should stop losing weight (unless the dog is an overweight Type II individual and part of the treatment plan is to slim down).

Part of the owner’s responsibility is to monitor and record their dog’s weight by checking it every other week. As a backup, a body condition score should be performed every month. In some cases, owners may also be asked to collect a urine sample (a cup on a pole is commonly used for the purpose) and use a special test paper to measure blood glucose.

With care and dedication, a diabetic dog can enjoy a long, active life without adverse effects.