My dog is a carnivore and his diet should not have carbohydrates.
Despite what is claimed on internet websites, the domestic dog is considered an omnivore in its feeding behavior, anatomy, and metabolism. The digestive tract of the dog is well adapted for use of carbohydrates in their diet and researchers have identified 10 genes that play roles in starch digestion. In fact DNA comparisons have demonstrated that several of these genes are more active in the pet dog when compared to the wild wolf because the domestic dog has been so closely associated with humans (~15,000 yrs) and has adapted to our foods. Carbohydrates in pet foods provide a readily available energy non-fat source, some B vitamins, fiber for intestinal health, affordability of ingredients, and shelf stability for products.
If you have more specific questions - Ask the Nutritionist.