Animal food recipes created by food manufacturers have to include ingredients (protein, carbohydrates, fats, vitamins, minerals, supplements) that make the food nutritionally balanced and complete. If you look on your dry or wet dog food, you’ll see a comment similar to: “this food is formulated to meet the nutritional levels established by the AAFCO Dog Food Nutrient profiles for adult maintenance”.
There are some foods designed for supplemental or intermittent use only (low phosphorus, low protein); these will have a different citation similar to: “this food is for supplemental and intermittent feeding only”. These foods should not be your dog’s long-term food as they are deficient in ingredients your dog’s body needs to function.
There is much disagreement whether AAFCO protects animals, or the animal feed manufacturers. Read Truth About Pet Food for some thought-provoking information and opinions about the animal feed industry.