Some research has pointed out that heating or cooking dog food destroys vital enzymes needed for fermentation and digestion. When dog food is sterilized for canning or cooked in kibble manufacturing, enzymes die. Brands claim that this can make it difficult for the food to be broken down and for nutrients to be absorbed. But wait, deciding to offer your dog digestive enzymes based on the "cooked or canned food" dilemma can also be disputed. Dr. Cailin Heinze, a Board Certified Veterinary Nutritionist, says the claims that cooked dog food lacks food enzymes and will therefore impact nutrient absorption are not valid. She says, "The enzymes naturally occurring in food have more to do with why food spoils than being necessary for digestion, so "killing" them by cooking isn't going to make any measurable difference for your pet."