Carbohydrates are present in almost all commercially available dog foods. While we often focus on the protein and fat content of a dog food, carbohydrates have an impact on the quality of your dog's diet.Carbohydrates are responsible for many health problems, if not fed correctly.he function of carbohydrates in pet food. The value of carbohydrates in dog foods is often debated among nutritionists. Despite the debate, most commercial dry foods contain between 30% and 70% carbohydrates.