So what exactly is in that pet food you are feeding?
Words and phrases found in the List of Ingredients (like “corn gluten meal” or “poultry by-product”) have very specific definitions within the pet food industry, but can seem vague and confusing for anyone on the outside. And many alternative pet food companies and self-appointed pet food “advice” websites will use misinformation and fear-mongering to promote their foods or philosophies. My hope is that by providing the actual legal definitions of pet food ingredients, it will help dog and cat caregivers (owners and veterinarians alike) make the best decisions they can when it comes to selecting a food for their beloved companion.
The word used for ingredient names in dog and cat foods are determined by laws adopted by individual states as recommended by the Association of American Feed Control Officials (AAFCO) Model Bill and Guidelines. AAFCO was founded in 1909 to help guide what was at the time a fledgling feed industry. Unfortunately (at least in my opinion), as pet ownership evolved over the last 105 years, the rules and regulations on pet food labels and ingredients haven’t quite kept up. The ingredient definitions that the pet food industry has to work with today are a relic of a time when most pet owners didn’t read any food labels, let alone quibbled about what exactly was in “meat by-product”.
Without further ado I will give you what I consider the not-so-secret ingredient definitions from the 2014 AAFCO Official Publication …
- Meat and Meat By-Product = From Regulation PF5; Ingredients (b): “The ingredients “meat” and “meat by-product” shall be qualified to designate the animal from which the meat and meat by-product is derived unless the meat and meat by-product are made from cattle, swine, sheep, goats, or any combination thereof.”
- Translation: “Meat” cannot be dog, cat, horse, road kill, etc, unless specifically named as such. If it isn’t beef, pork, sheep (lamb/mutton), or goat it cannot legally be included as “meat” or as a “meat by-product”.
- Meat = From Official Names and Definitions of Feed Ingredients; Item 9.2: “Meat is the clean flesh derived from slaughtered animals and is limited to that part of the striated muscle which is skeletal or that which is found in the tongue, in the diaphragm, in the heart, or in the esophagus; with or without accompanying and overlying fat and the portions of skin, sinew, nerve, and blood vessels which normally accompany flesh. It shall be suitable for use in animal foods. If it bears a name descriptive of its kind, it must correspond thereto. (Adopted 1938, Amended 1939, 1963).”
- Translation = It is the muscle and similar type animal proteins from any combination of cattle, swine, sheep and goats (if labeled as “meat”) or the muscle protein from a specifically named food animal that hasn’t made its way into the human food supply chain. Not because these meats are unfit for human consumption, but because people in the US are squeamish about eating them (mmm, tongue…) or they are not economically feasible to sell as a human food.
- Meat By-Product = From Official Names and Definitions of Feed Ingredients; Item 9.3: “Meat by product is the non-rendered, clean parts, other than meat, derived from slaughtered mammals. It includes, but is not limited to, lungs, spleen, kidneys, brain, livers, blood, bones, partially defatted low temperature fatty tissue, and stomach and intestines, freed of their contents. It does not include hair, horns, teeth and hoofs. It shall be suitable for use in animal food. If it bears name descriptive of its kind, it must correspond thereto. (Proposed 1973, Adopted 1974, Amended 1978)”
- Translation: “Meat By-Product” is the edible, non-muscle meat protein portions of cattle, swine, sheep, goats, or “any combination thereof” that is not eaten widely by people in the US. It specifically excluded intestinal “contents” (i.e., poop) as well as the non-digestible parts on the animal. The internal organs like liver and kidney are typically what ends up in pet food and are the primary component of “by-product”, but these vitamin and mineral rich foods would otherwise go to waste in the US (we don’t eat much liver and onions now days…). It can technically include brain, but because of BSE concerns, brain is not a common component of “by-product”.
- Poultry = From Official Names and Definitions of Feed Ingredients. Item 9.57: “Poultry is the clean combination of flesh and skin with or without accompanying bones, derived from parts of whole carcasses of poultry or a combination thereof, exclusive of feathers, heads, feet or entrails. It shall be suitable for use in animal food. If it bears a name descriptive of its kind, it must correspond thereto. If the bone has been removed, the process may also be so designated by use of appropriate feed term. (Proposed 1978, Adopted 1979, Amended 1995, Amended 1997).”
- Translation: Poultry can technically be any bird species used in food animal production such as chicken, duck, turkey, quail, ostrich, or emu, although the reality is that it is almost always chicken, duck and turkey (with or without bone) that haven’t made their way into the human food supply chain. This is not because these poultry proteins are unfit for human consumption, but because people in the US only want to eat breast, leg/thigh, and wing meats and the rest of the frame needs to go somewhere. It is also important to note that bone is allowed unless the Pet Food Company specifically tells you so on the List of Ingredients.
- Poultry By-Product = From Official Names and Definitions of Feed Ingredients; Item 9.12: “Poultry By-Product must consist of non-rendered clean parts of carcasses of slaughtered poultry such as heads, feet, viscera, free from fecal contents and foreign matter except in such trace amounts as might occur unavoidably in good manufacturing practice. If the product bears a name descriptive of its kind, the name must correspond thereto. (Proposed 1963, Adopted 1964, Amended 2000).”
- Translation: It is everything except the frame meat from a chicken, duck, and/or turkey, but specifically not poop (“fecal contents”). Yes, it can include heads and feet, but the reality is that poultry producers will usually get a higher price for heads and feet on the “ethnic” food market for human consumption (mmm, chicken feet…) than they will from the Pet Food Companies. The internal organs are typically what end up in pet food and are the primary component of “by-product”, but again these vitamin and mineral rich foods would otherwise go to waste in the US.
- Poultry By-Product Meal = From Official Names and Definitions of Feed Ingredients. Item 9.10: “Poultry By-Product Meal consist of ground, rendered, clean parts of carcasses of slaughtered poultry such as necks, feet, undeveloped eggs, and intestines, exclusive of feathers, except in such amounts as might occur in good manufacturing practices. …[guaranteed amounts of specific nutrient are listed next, but I’ve left them out here]… If the product bears a name descriptive of its kind, the name must correspond thereto. (Proposed 1985, Adopted 1990, Amended 2000).”
- Translation: I don’t know why there are two different lists of what can be included in fresh vs. processed “poultry by-products”, but there are and there are some key differences between the two. The biggest being that chicken poop (“fecal contents”) is specifically excluded from fresh “poultry by-products”, but feathers are what is excluded “poultry by-product meal”. So if you follow the letter of the law, “poultry by-product meal” can include poultry feces, while “poultry by-product” can include feathers, but not vice-versa. Weird distinction, but now you know.
- Rendering = From Official Feed Terms: “cooking and separating process in which conditions such as time and temperature, with or without pressure, are sufficient to remove water, kill pathogenic microorganisms, and separate fats and oils from other components.”
- Translation: Meals are the dehydrated, defatted product of cooking an ingredient prior to incorporation into pet foods. Depending on the source protein, “meals” can be good ingredients or bad. Using animal protein “meals” allows for a very specific and consistent amount of protein in the diet without the worries of water or fat fluctuations that can affect formulation using fresh meats (of any kind), but the rendering process can alter the structure of essential amino acids making them less digestible and create a nutrient deficiency if not corrected by the manufacturer.
- Adulteration , Model Bill and Regulation
- Section 7 (a) (7): “If it consists whole or in part of any filthy, putrid, or decomposed substance, or if it is otherwise unfit for feed”
- Section 7 (a)(9): “If it is, in whole or in part, the product of a diseased animals or of an animal that has died otherwise than by slaughter”
- Translation: Only healthy food animals and non-disease parts can be included in pet foods, anything else is considered an “adulterant” and subject to legal action against the manufacturer or raw material provider. The truth about the types of animal proteins that can legally be added to pet foods is not nearly as exciting and head-line grabbing as telling pet owners that “4D” meats go into main stream pet food (4D=dead, dying, diseased and disabled if you haven’t heard this term before).
- Gluten = From Official Feed Terms: “The tough, viscid nitrogenous substance remaining when the flour of wheat or other grain is washed to remove the starch.”
- Translation: Gluten is just the generic term for protein from grains. People who have “gluten” sensitivities or Celiac Disease are actually reacting to the proteins gliadin and glutenin that are specific to wheat, rye, and barley (grains in the wheat family); these are not found in corn or rice at all, so “corn gluten” or “rice gluten” can be eat by people with documented “gluten” problems.
- Brewers Rice = From Official Names and Definitions of Feed Ingredients. Item 75.4: “Chipped Rice, Broken Rice, or Brewers Rice is the small fragments of rice kernels that habe been separated from the larger kernels of milled rice.”
- Translation: The less aesthetically pleasing pieces of rice that don’t end up in people foods. I love that the other synonymous terms are “broken” or “chipped” rice. I can understand why Pet Food Companies prefer the term “Brewers Rice” instead.
As a Veterinary Nutrition Specialist the only times I run into problems with some of these ingredients is when I encounter a dog or cat with food allergies or with liver dysfunction. For animals with suspected food allergies previous diets that included “meat” and/or “poultry” on the List of Ingredients could potentially contain any combination of beef, pork, lamb, goat, chicken, duck and turkey, so I need to avoid all of them in the new diet; “Poultry By-Product Meal” can also include eggs, so now I have to add that to the list of foods to avoid, too. Animals with liver disease should not be fed diets with any “By-Products” since feeding organ meats (especially liver!) may worsen their clinical signs and increase the risk of developing hepatic encephalopathy or urate bladder crystals/stones. And the only times I worry about “Gluten” is if has been contaminated with melamine and cyanuric acid, which shouldn’t happen now that Pet Food Companies are testing for these potential contaminants, or if I have an animal with a suspected food allergy to that particular plant protein.
So why do some Pet Food Companies continue to use these vague, often misinterpreted ingredient names? My theory is that these terms were originally adopted into the AAFCO guidelines (1938 for the oldest, 1985 for the newest) at a time when pet owners wanted to buy the lowest cost food for their dogs and cats and the specific ingredients had little to no importance as long as the food was safe and healthful. BY using these general ingredient terms Pet Food Companies could provide a least-cost food that easily complies with label regulations. If a Pet Food Companies makes a food with “Meat”, “Poultry” or “By-Product” then they have what would I would considered an “open formulation” and are legally allowed to substitute nutritionally comparable ingredients depending on cost and ingredient availability, without having to submit new product approval to the FDA first. If a Pet Food Company lists specific animal ingredients (like “Beef” or “Chicken”) then they have what I consider a “closed formulation” and any substitution to a specifically name ingredient list would be considered an “adulteration” and would be illegal unless they obtain prior approval, a process that can take months to years. These two methods of developing a pet food formulation are equally nutritious. “Open formulation” are easier and less expensive from a production standpoint, but are a pain when trying to find a novel diet to manage a suspected food allergy.
The take-home message…
Every ingredient used in a pet food is a “by-product” of the human food supply chain. If it wasn’t, only the very wealthy would be able to feed their pets (or themselves!) and we would have an even larger problem with food waste than we already do. Personally, I don’t have a problem with pet food manufacturers using the clean, edible parts of plants and animals that people would otherwise discarded, this is the ultimate in eco-friendly, sustainable feeding practices. I just wish you could walk down the pet food aisle without needing to consult the AAFCO Office Publication to understand the ingredient list!
Lisa P. Weeth, DVM, MRCVS, DACVN