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Why are meat byproducts used in pet foods? What are byproducts? Are byproducts bad for my pet?


  • No – if byproducts are appropriately utilized in the manufacturing process they are an excellent source of nutrients.
  • Byproducts definition: “secondary products produced from principle products” according to the Association of American Feed Control Officials (AAFCO) Official Publication, 2011.1 Beet pulp, tomato pomace, and Vitamin E (a byproduct of soybean processing) are all examples of byproducts.
  • Meat byproducts are commonly used ingredients in pet foods.
  • Meat byproducts definition: clean parts of slaughtered mammals (i.e. liver, hearts, lungs, spleen, kidneys, tripe, etc).1
  • Meat byproducts are the parts of animals that U.S. meat consumers have decided not to eat but are considered delicacies in other cultures.2
  • Wild canids will consume “byproduct” protein sources first after a successful hunt.2
  • Byproducts are used in pet foods because they are excellent sources of protein and other nutrients.
  • Byproducts (i.e. liver) “taste” better to dogs compared to muscle meats when used in foods.3

More supporting facts:

  • Byproducts are common ingredients in human food (i.e. gelatin, liver, flaxseed oil, corn oil, beef bouillon).
  • Poultry byproduct: clean parts of the carcasses of slaughtered birds: muscle, skin, viscera. No feathers, according to the Association of American Feed Control Officials (AAFCO).1
  • Animal byproduct meal: clean animal tissues. No hair, hoof, horn, manure, stomach, or rumen contents (AAFCO definition).1
  • Meat byproducts do not include hair, horn, teeth, or hooves.1
The Science Behind our Recommendations
1. Association of American Feed Control Officials. 2011 Official Publication. Association of American Feed Control Officials, Inc. 2011: 355,  369, 374. 2. Thompson A. Ingredients: where pet food starts. Top Companion Anim Med. 2008 Aug; 23(3): 127-32. 3. Crane SW et al. Commercial Pet Foods. In: Hand MS, Thatcher CD, Remillard RL, Roudebush P, Novotny BJ, eds. Small Animal Clinical Nutrition 5th ed. Topeka, KS: Mark Morris Institute; 2010: 173.