By Wendy C. Brooks, DVM, DipABVP
Educational Director, VeterinaryPartner.com
A lot of information has recently been published about high protein diets in managing diabetes mellitus in cats. It may be tempting to try to apply similar rules to dogs but, in fact, an entirely different approach is needed. Canine diabetes mellitus is more like Type I or insulin-dependent diabetes in humans, while feline diabetes is more like Type II. What this means is that the canine pancreas is not producing any insulin at all while the feline pancreas isn’t producing enough. The dietary approaches are very different.
Classically, high fiber diets have been recommended for the management of canine diabetes mellitus. More recent scrutiny of fiber has led to conflicting results. In many cases, addition of insoluble (non-digestible) fibers to the diet helped glycemic control, meaning that blood sugars were more stable throughout the day.
Fiber blunts the increase in blood sugar levels that occur after eating, delays the emptying of food from the stomach, and slows the digestion of carbohydrates (glucose sources). All this means that blood sugar levels are inclined not to jump as high after eating compared to those of patients fed low fiber diets.
If the diabetic dog is overweight - and many are - fiber also helps the patient feel full after eating, thus encouraging weight loss. This may not be so desirable in a diabetic dog that is underweight, and many are.
High Digestibility Diets: Probably not the Best Thing
There are numerous diets on the market designed for dogs with “sensitive stomachs.” These foods typically are designed for easy digestion and absorption. While this is helpful to dogs with digestive issues, easy digestion and absorption amounts to higher blood glucose levels after eating. This is probably not the best thing for a diabetic dog.
A common issue that accompanies diabetes mellitus is elevated triglycerides (fats) in the bloodstream. In humans, this is the doorway to vascular disease, cholesterol deposits, heart disease and stroke. Dogs do not generally have to contend with these issues but the elevated fat levels in the blood can lead to pancreatitis, which is a serious disease. Many nutritionists recommend that metabolizable energy of a diet not exceed 30% fat, but this information is not readily available on a pet food label. Protein recommendations should be 18-25% in the diet on a dry matter basis.
To calculate the percentage of protein in a diet on a dry matter basis, look for the crude protein and the moisture content amounts in the guaranteed analysis on the food label. Multiply the moisture content by the crude protein and subtract that number from the crude protein. (Example: a food is 20% crude protein and 10% moisture. Multiply 20 x 0.10 = 2. Subtract 2 from 20. The answer is 18% protein on a dry matter basis.) If the food is dry, there is typically so little moisture content that the numbers off the label approximate the dry matter percentages. If the food is canned, though, the food might be 80% water and calculation becomes more important.
As long as the diet is consistent, it is generally possible to work with it in achieving diabetic regulation. Here are some additional tips:
- If the dog has an additional medical problem that requires a specific diet in its management, then this trumps the suggestions for diabetic management.
- As long as a reputable food that has passed AAFCO feeding trials is being fed, it should not be necessary to add nutritional supplements.
- Soft-moist foods typically use sugary preservatives and should be avoided. Canned and dry foods are equally acceptable.
- Ideally, a brand of food with a “fixed formula” is preferred to one with an “open formula.” Foods with an open formula stick to their prioritized ingredient list on the label and to the guaranteed analysis minimums and maximums, but the exact ingredient amounts are not fixed. A fixed formula food uses specific amounts of each ingredient every time in every lot. In general, non-prescription diets are open formula diets.
Your veterinarian can help you choose the most appropriate food for your diabetic dog.