Dietary treatment for pets with Type 2 diabetes (also referred to as non-insulin-dependent diabetes or NIDDM) can be instrumental in improving glycemic control and preventing the need to institute exogenous insulin therapy. Factors that must be considered when developing an appropriate diet for a diabetic pet include the consistency and type of diet, its nutritional adequacy and nutrient composition, and the pet’s caloric intake and feeding schedule.

Dogs and cats with diabetes should be fed food that contains consistent amounts and source of nutrients. Specifically, the type and quantity of nutrients that are delivered to the body should remain consistent from day-to-day, and the proportions of calories in the diet that are supplied by carbohydrate, protein, and fat should stay constant.

For pets with IDDM, the provision of a consistent diet allows the insulin dosage to be adjusted to closely fit the needs of the animal. Similarly, if pets with NIDDM are being treated with oral hypoglycemic agents, the provision of a consistent diet is helpful in maintaining normal blood glucose levels.

Changes in the ingredients or nutrient composition of a diet can disrupt the tight coupling of blood glucose levels with insulin activity that is needed for proper glycemic control. Therefore, only pet foods that are prepared using a fixed formulation should be selected for diabetic pets.

Manufacturers that use fixed formulations ensure that the nutrient composition and ingredients of a food remain consistent between batches. In contrast, manufacturers that use variable formulations will change ingredients depending on the availability and market prices. If information about the formulation type is not readily available, it can be obtained by contacting the manufacturer directly. Homemade diets should also be avoided with diabetic pets because of difficulties with maintaining nutrient consistency.

The type of commercial product that is fed is also of importance. Semimoist pet foods or snacks should not be fed to diabetic pets. Postprandial blood glucose and insulin responses have been shown to be highest when dogs are fed either canned or dry pet foods. This increase appears to be because of the high level of simple carbohydrate found in semimoist products. These nutrients require minimal digestion in the small intestine and are rapidly absorbed following a meal.

In contrast, the digestible carbohydrates found in dry and canned foods are made up primarily of complex carbohydrates (starch). Starches require enzymatic digestion to simple sugars before they can be absorbed into the body.

This process slows the rate of delivery of glucose to the bloodstream. Complex carbohydrates and certain types of fiber also affect the rate of food passage through the gastrointestinal tract and the absorption of other nutrients in the diet. Dry pet foods generally contain higher levels of both complex carbohydrates and plant fiber than semimoist or canned foods do.

A lack of insulin activity leads to elevated blood glucose levels (hyperglycemia) and an inability of tissues to receive the glucose that they need (glucoprivation). Primary clinical signs include polyuria, polyphagya, polydipsia, and weight loss. Diagnosis is usually made using the initial signs of the disorder, which are the presence of a persistent hyperglycemia and a persistent or concurrent glycosuria.

It is estimated that diabetes has an incidence between 0.2% and 1% in dogs and cats seen at small animal clinics. A large proportion of these diabetic pets are obese at the time of diagnosis. In dogs, other factors that appear to be related to the development of diabetes are hormone abnormalities such as hypothyroidism and Cushing’s syndrome, recurrent episodes of pancreatitis, pancreatic islet-cell destruction, stress, and genetic predisposition.

In cats, the most significant risk factor for the development of diabetes is increasing age. Between 70% and 90% of diabetic cats are 7 years or older and more than 65% are 10 years or older. Other predisposing factors for cats include inactivity, presence of pancreatic neoplasia, long-term administration of progesterone or progestin, and possibly, genetics.

All of the clinical signs observed in pets with diabetes are associated with the short or long-term effects of hyperglycemia. The microvascular effects of diabetes contribute to the development of cataracts and renal disease. Polyneuropathy develops in some cases and can manifest as weakness, depression, or uninary and bowel incontinence. Bacterial infections are common in animals with poor glycemic control. All of these complications can be minimized or prevented through stringent control of blood glucose levels in diabetic animals.

The general therapeutic goals in diabetes management are to minimize post-prandial (after-meal) hyperglycemia, prevent hyperglycemia when insulin is being administered, resolve and minimize clinical signs, prevent or delay long-term complications, and improve overall health. These goals can be achieved through exogenous insulin administration, oral hypoglycemic agents, diet, weigh loss (if indicated) exercise, and the control of concurrent illness.