There is a significant difference between humans and dogs in their need for carbohydrates and in their ability to digest them. The digestive tract of a human is longer than that of a dog, and the formation of jaws and teeth is entirely different. A dog’s digestion starts in the stomach. Dogs’ teeth – all 42 of them – are built to tear flesh apart. Dogs gulp their food as fast as they can, which then reaches the stomach with no digestion having taken place.
Human digestion starts in the mouth. A human chews food with 32 teeth, which have flat surfaces for grinding and breaking down food. Enzymes contained in the saliva contribute to this breakdown of the food, which is being digested before it reaches the stomach.
Carbohydrates come in two forms, simple and complex. Simple carbohydrates come from grains such as wheat, corn, rice, oats, soy and millet. They break down into starches and sugar when properly cooked. Complex carbohydrates come in the form of various fibers such as brans, hulls and peanut shells from the outside of plants. A small amount is needed for proper digestion and stool formation. Nutrients are obtained from both sources, but most come from simple carbohydrates.
If carbohydrates are a major part of your dog’s diet, the time and energy needed for digestion increase, the dog performs less well, large amounts of stool are produced, and a protein deficiency disease may develop. Dogs have evolved as meat eaters and although they need some grains, their health and longevity will be better served on a diet containing more animal protein than protein from grains.
Think about the origin of the dog. It is unrecorded in history that wolves lit fires and cooked grains picked in fields! But there were whole carcasses available that contained everything needed for wolves to survive, including predigested vegetable matter in the intestinal tracts of their prey.
The reason the majority of dry dog foods contain such large amounts of cereal grains is that grains are a cheap source of nutrients. According to the NRC guidelines, “Carbohydrates provide an economical source of energy in the diet of dogs.”
Allergic reactions to grains are common in dogs. The best diet for your dog matches that fed in the breed’s country of origin as the breed developed. Each dog is an individual, and if yours refuses to eat his food, check the grains listed on the package. The dog may balk because of an allergy to one of the grains in the food.