Frequently Asked Questions Regarding Diabetes

Q

A

Do diabetic dogs have significant postprandial hyperglycemia? If they do, how long does it last?

Yes. In non-diabetic dogs, commercial dog foods usually result in postprandial elevation of blood glucose concentration for less than 90 minutes. Diabetic dogs lack endogenous insulin secretion, resulting in failure of the major physiological mechanism for counter-regulation of increasing blood glucose concentration. Consequently, postprandial hyperglycemia in diabetic dogs is of greater magnitude and duration compared with non-diabetic dogs.

When should diabetic dogs be fed in relation to administration of insulin injections?

Therapy with exogenous insulin has a marked effect on postprandial hyperglycemia. Insulin administration and meal feeding should ideally be timed so that maximal exogenous insulin activity occurs during the postprandial period. Thus, dogs should be fed within 2 hours of subcutaneous administration of lente insulin or within 6 hours of protamine zinc insulin(Figure 2a & Figure 2b). A feasible compromise is to feed the dog immediately following the insulin injection. This considerably simplifies the home treatment regimen for most dog owners while still allowing good glycemic control to be readily achieved. In addition, many owners prefer this regimen because they feel their pet is rewarded for submitting to the injection.

What should be done if a diabetic dog will not eat?

It is crucial that the food fed to diabetic dogs is highly palatable so that food intake is predictable. If the diet is not palatable, it should be changed to a formulation that is more acceptable to the dog. Whenever an individual diabetic dog does not reliably consume meals when they are fed, it should be recommended that insulin injections are administered immediately after meal feeding. If the dog consumes the meal, the full insulin dose can be administered. If the dog refuses to eat, then administration of half the usual insulin dose should be recommended to reduce the risk of hypoglycemia. If a diabetic dog refuses to eat a meal that it usually finds palatable, the possibility of concurrent illness should be considered and veterinary examination is recommended.

Can diabetic dogs be fed ad libitum or should they all be meal fed?

Diabetic dogs should ideally be fed a set number of meals per day. The daily insulin-dosing regimen tends to be fixed for diabetic dogs, and the timing of meals should be matched to insulin administration so that a predictable glycemic response occurs at the time of maximal exogenous insulin activity. Thus, meals should be fed at the same times each day. Severe hypoglycemia has been reported in a diabetic dog that was fed ad libitum and received insulin at grossly irregular intervals (Whitley et al., 1997). The majority of diabetic dogs will readily consume meals twice-daily if the meals are highly palatable and contain half the daily caloric requirement. For finicky eaters, the meal should be fed at the time of insulin administration and remain available until the expected end of the period of maximal exogenous insulin activity.

Can the meals fed to a diabetic dog be varied from day to day?

Ideally, every meal should contain the same ingredients and calorie content. This is an important aspect of diabetes management in dogs and owner compliance should be encouraged. However, care should be taken to consider each case individually. It is usually possible to allow some changes in the feeding regimen without compromising the clinical response of the dog.

What is the recommended fiber content of diets fed to diabetic dogs?

There is no evidence of clinical benefit for diabetic dogs of feeding a high-fiber formulation compared with feeding a typical adult maintenance diet. There is marked variation between the responses of individual diabetic dogs to dietary fiber. Some diabetic dogs will have improved glycemic control when fed diets with an increased amount of dietary fiber, while others will not. The response to dietary fiber must be individually assessed in each case. Increased dietary fiber intake is not recommended for diabetic dogs that are underweight, or for dogs for which fiber-supplemented formulations are unpalatable or associated with unacceptable gastrointestinal side-effects. The most suitable general dietary fiber recommendation for diabetic dogs may be moderate-fiber formulations (for example, 35 g/1000 kcal), although further research is required to demonstrate clinical benefit of this formulation for diabetic dogs compared with typical commercial dog foods formulated for adult maintenance.

Is a low-carbohydrate, high-protein diet now recommended for diabetic dogs similar to the current recommendation for diabetic cats?

Dogs and cats are prone to different types of diabetes and also have different basic macronutrient requirements. Diabetic dogs have forms of diabetes analogous to both human type 1 diabetes and end-stage pancreatitis, while diabetic cats have a form analogous to human type 2 diabetes. There is no evidence that type 2 diabetes occurs in dogs, so it is not valid to extrapolate information on either this disease or feline diabetes to dogs. Unlike dogs, a large proportion of diabetic cats have sufficient beta cells to allow diabetic remission if glucose toxicity and its associated insulin resistance can be reversed, and there is evidence that remission rates are higher if diabetic cats are fed a low-carbohydrate diet. This does not apply to dogs. Diabetic dogs have absolute insulin deficiency and require life-long therapy with exogenous insulin. As a regimen of fixed daily insulin dosages is typically used to manage diabetic dogs, it is rational to provide a very consistent amount of starch in the meals fed each day.

What is the best method to achieve body weight gain in a thin diabetic dog, and weight loss in an overweight diabetic dog?

Caloric intake in diabetic dogs should be adjusted to achieve and maintain an ideal body condition. Dogs with poorly controlled diabetes have a decreased ability to metabolize the nutrients absorbed from their gastrointestinal tract and loose glucose in their urine, so require more calories for maintenance than healthy dogs. Most dogs have weight loss by the time diabetes is diagnosed. Many will be underweight while others might still be obese even though they will have experienced weight loss. Insulin therapy ends this state of catabolism and weight loss will soon be arrested. At this stage, a weight management program can be initiated. Body weight and body condition should be monitored regularly in all diabetic dogs and caloric intake should be adjusted at each re-evaluation until the desired rate of gain or loss is achieved. If a diabetic dog fails to gain weight when there is good glycemic control and adequate caloric intake, concurrent disease such as exocrine pancreatic insufficiency should be considered. Conversely, a possible cause of obesity in treated diabetic dogs is excessive insulin dose, because insulin has an anabolic action on adipose tissue.

What diet is recommended for diabetic dogs with recurring pancreatitis or exocrine pancreatic insufficiency?

Dietary therapy for recurring pancreatitis or exocrine pancreatic insufficiency is usually a higher clinical priority than dietary therapy for diabetes. The prognosis might be improved if these concurrent conditions are recognized early in diabetic dogs and specific nutritional and medical therapy instituted. The dietary recommendations for exocrine pancreatic diseases can be found in Chapter 5 of this encyclopedia.