Although dogs do not need carbohydrates because their bodies can get energy from protein and fats alone, carbohydrates that can be broken down by the digestive system and converted to glucose can also be a source of energy. (Carbs can be the main caloric source in some dog foods.)
Carbohydrates in the form of whole grains can furnish iron, minerals and fiber as well as other beneficial nutrients. Since cooking determines starch digestibility, and therefore its availability, starches need to be well cooked; otherwise, they tend to ferment in the large intestine. Carbohydrates can be found in vegetables and fruit, which also supply minerals, fiber, antioxidants, phytochemicals and some protein.