What Are Animal Byproducts in Dog Food?

Animal byproducts are the nonmeat, leftover parts of different types of mammals after processing for human consumption contained in dog food as a source of protein. Dogs require protein in their diet from meats to obtain amino acids, some of which contain more than others. The least desirable commercial dog foods list animal byproducts as a main ingredient, because these byproducts contain a low amount of digestible amino acids.

  1. Identification

    • The Association of American Feed Control Officials, an agency that sets standards for the nutrition content and safety of ingredients contained in pet foods, provides definitions for ingredients contained in pet foods. AAFCO defines animal byproducts as the nonmuscle parts of an animal, including the animal's lungs, spleen, kidneys, brain, livers, blood, bone, partially defatted low-temperature fatty tissue, stomachs and intestines freed of their contents. Because animal byproducts also include poultry byproducts, they can include the heads, feet, necks, undeveloped eggs, and intestines of different types of birds. Most of these ingredients aren't fit for human consumption and contain low amounts of nutrients and amino acids, according to Ann Martin, author of "Food Pets Die From: Shocking Facts About Pet Food."

    Quality

    • The Food and Drug Administration requires pet food manufacturers to list ingredients on the label of the food in order of weight. Lower-quality foods list meat byproducts first, ingredients that are harder to digest for dogs and have less nutritional value, according to The Dog Food Project. If not identified specifically, the general term "animal byproducts" can contain any slaughtered animal and doesn't include hair, horns, teeth and hoofs, the AAFCO defines. Foods that contain animal or poultry byproducts are more desirable than those that contain grains, a less digestible source of protein for your dog, according to PetEducation.com.

    Nutritional Value

    • Because animal byproducts contain no whole meat, they have low nutritional and biological values for your dog. These ingredients contain high levels of protein and meet AAFCO standards for nutritional ingredients, but contain less amino acids than whole meats or eggs, PetEducation.com states. You can find animal byproducts in canned and dry dog foods. These ingredients are acceptable in smaller amounts, if the main components of the food come from whole, specifically identified meats. If you can, avoid byproducts or choose those listed by specific type, such as chicken or beef.

    Considerations

    • Although banned from human consumption by the FDA, pet food manufacturers can include meat and byproducts from dead, dying, diseased, and disabled animals, known as 4D, in pet food, Betsy Brevitz writes in "The Complete Healthy Dog Handbook." Continuous feeding of dog food containing a majority of these leftover meat-parts can lead to diarrhea, gas, vomiting and even disease in the long run, according to Jean Callahan, author of "Your Older Dog: A Complete Guide to Helping Your Dog Live a Longer and Healthier." Pet foods labeled "only USDA certified meat" must contain meats or byproducts fit for human consumption, not 4D meats, Brevitz writes.