The long-term goal of this column is to teach interested dog owners how to formulate safe and wholesome “complete and balanced” home-prepared diets for their dogs. We will eventually cover raw and cooked diets, diets that use raw bone as a calcium source, and diets that use other sources of calcium, as well as diets that contain grain and diets that are grain-free. The one thing that all of these diets will have in common is that they will all be “complete and balanced” as defined by the Association of American Feed Control Officials (AAFCO).
Why would we suggest using nutritional guidelines developed for commercial pet foods, when the whole reason we want to teach people to make their own pet food is so they can provide their dogs with diets that offer better safety and nutrition than commercial foods?
The short answer is that these standards, imperfect as they may be, are better than no guidance at all. Many books and Internet articles make the preparation of home-prepared diets sound as easy as pie. But the truth is, it’s astonishingly easy to feed (or even overfeed!) your dog while simultaneously starving him of nutrients that he needs in order to live a healthy, long life. Most recipes we’ve analyzed are deficient in critical nutrients. We consider the AAFCO nutrient guidelines for pet food to be a good starting point—the bare minimum of what should be provided to our dogs.
Providing All the Nutrients Your Dog Needs
Most dog owners feed their dogs the same food, day in and day out, often for years at a time. Even people who feed a home-prepared diet are prone to fall for the convenience of a recipe that they replicate daily or weekly without variation. It’s more important than ever that a diet meet at least minimum nutritional guidelines when dogs are fed in this way!
Human diets and recipes are rarely formulated to provide 100 percent of the nutrients determined to be essential for human health. But humans rarely rely on a single recipe or unvarying diet; most of us eat a wide range of fruits, vegetables, grains, various protein and fat sources, and other foods, plus we have the opportunity to respond to our body’s cravings when something is missing.
In contrast, our companion animals are completely reliant on us to put everything their bodies require into their food bowls. If we feed them the exact same diet every day, and that diet fails to provide adequate amounts of certain nutrients, or provides a potentially dangerous surplus of other nutrients, or even an imbalance between certain nutrients, we may well cause the development of disease. When feeding our dogs the same food every day, it’s all too possible for us to meet their caloric needs without properly nourishing them over time.
When you feed the same food or recipe every day, the importance of the food or recipe meeting AAFCO guidelines becomes magnified.
In last month’s installment of this column, “Cold, Raw Truth,” we were concerned that most high-fat commercial raw diets do not actually meet AAFCO guidelines when their nutrients are properly reported on a caloric basis. But if you combine commercial raw diets with other types of complete diets or recipes, particularly those that are lower in fat, you greatly reduce or even eliminate the issues we found, especially if you also vary the meats you feed.
Our goal with that article was not to say that you should not feed those foods; only that you should be cautious about feeding them exclusively, especially to the most vulnerable dogs, which include growing puppies, pregnant and nursing females, and older dogs who eat less than they once did.
Nutrient Guidelines for Dogs
Recommended Dietary Allowances (RDAs) for humans were first published in the U.S. in 1943. They were intended to reflect the best scientific judgment on nutrient allowances for the maintenance of good health and to serve as the basis for evaluating the adequacy of diets and preventing diseases linked to nutritional deficiencies, such as rickets, scurvy, beriberi, pellagra, and goiter. As knowledge of nutrition advances, these recommendations are modified.
It wasn’t until 1974 that the National Research Council (NRC, the research arm of the National Academy of Science) published its first nutritional guidelines for pet food. Of course, the major players in the nascent pet food industry had been researching pet nutrition for a few decades before this, but much of the research had been directed at determining what pets could and would eat. The NRC’s Nutrient Requirements of Dogs and Cats has been updated a couple of times since then; the most recent version was published in 2006.
The nutritional guidelines used by pet food regulators in this country, however, are not the NRC’s; instead, state feed officials (pet food is regulated on a state-by-state basis) use a set of guidelines produced by AAFCO.
The AAFCO nutrient guidelines have been characterized as being more friendly to the pet food industry than NRC’s pet food nutrient guidelines, but AAFCO would likely describe the differences as acknowledgment of the realities of pet food ingredient sourcing and pet food production. The NRC guidelines are often based on studies using highly purified ingredients, with near-perfect availability and digestibility.
But “uncompromised” availability of all nutrients cannot be assumed or guaranteed in diets comprising typical commercial pet food ingredients. AAFCO puts it like this:
“The AAFCO Dog and Cat Food Nutrient Profiles were designed to establish practical minimum and maximum nutrient levels for dog and cat foods, formulated from non-purified, complex ingredients. These levels differ from the values developed by the NRC… Values for specific nutrient concentrations were added or modified where indicated and supported by recent scientific publications, practical experience, and unpublished data.”
The values were also modified based on known effects of ingredients and processing and the potential for lower digestibility in some products.” As a result, AAFCO minimum values are generally higher than NRC’s.
Neither AAFCO nor the NRC directly conduct nutritional research; rather, their respective guidelines are developed by committees comprised of (volunteer) animal nutrition experts who study all available relevant research on each nutrient. The experts compare studies, looking for consensus in the data and trying to reconcile major differences in research results. Their goals are the same: to try to find results that support the establishment of minimum (and, in some cases, maximum) values of every nutrient needed by dogs of various ages and reproductive stage to maintain health and prevent disease.
Though we will sometimes reference the nutrient values recommended by AAFCO to those suggested by the NRC (and even the ones recommended by the European Pet Food Industry Federation, FEDIAF), our diet recommendations and formulations will be crafted with the AAFCO guidelines in mind, for consistency and to be certain that they meet the most rigorous standards.
Criticism of the AAFCO Guidelines
The AAFCO guidelines aren’t perfect by any means. Just a few of the more salient criticisms of them include:
The organization is painfully slow to adopt changes that reflect newer research; the current guidelines date back to 1995! They have been arguing over and delaying implementation of changes based on the 2006 NRC updates for more than eight years now.
The guidelines are incomplete. As just one example, the benefits of omega-3 fatty acids in dogs have been recognized for quite some time, but they are still not included in current AAFCO nutrient guidelines. Proposed changes recently approved and due to be implemented in 2016 will include, for the first time, a minimum requirement for EPA and DHA (the omega-3 fatty acids found primarily in fish and other animal products) and ALA (the omega-3 fatty acid found primarily in plants), and a maximum ratio of omega-6 to omega-3 fatty acids.
Current AAFCO guidelines include maximum values for nutrients that can cause very serious adverse effects at high doses, such as iron, copper, and zinc. But the new AAFCO guidelines have removed many of these maximum values due to questions about bioavailability of different sources, and lack of research on exactly how much is too much. When maximum values are provided, several are more than 30 times higher than minimum values.
As a result, some “complete and balanced” foods may contain excessive and potentially dangerous amounts of some nutrients, such as copper in diets that contain beef liver, as we discussed last month. Most people (including many veterinarians) consider all foods with the designation “complete and balanced” as equivalent, unaware that, without maximum values to limit the range of what can be qualified as within the guidelines, or even with maximum values that allow a very wide range, the difference between nutrient levels in one product and another might have serious effects on a given animal’s health. For this reason, we also refer to European (FEDIAF) legal limits when analyzing recipes and diets.
AAFCO guidelines rely heavily on the use of synthetic supplements and may not apply well to nutrients derived from whole foods. But without adequate research on whole food diets, there’s no way to know for sure which nutrients may be acceptable at lower levels, and which will lead to deficiencies that affect a dog’s health or longevity.
Steve Brown, one of the contributors to this column, is a proponent of what he calls an “ancestral diet” for dogs (he wrote a book about it, called Unlocking the Canine Ancestral Diet: Healthier Dog Food the ABC Way, 2010 Dogwise Publishing). Drawing on the research of five scientists who studied the diets of wild canids (mostly wolves), Brown analyzed the nutrient levels in a wide variety of reconstructed wild canid diets. In a strange sort of confirmation of the work of the AAFCO nutrient guideline committees, he found that his re-created ancestral diets met essentially all of the AAFCO nutrient guidelines, particularly when it came to minerals (see Table I below).
There are many people who feed a variety of diets (with and without bones, organs, vegetables, dairy products, eggs, etc.) to their dogs in an effort to replicate their own versions of a “biologically appropriate raw foods” or ancestral-style diet, ignoring standards from AAFCO, NRC, and FEDIAF, because they think those regulatory guidelines are not important or relevant. Brown has analyzed hundreds of home-prepared diet recipes and found that they frequently fail to reach many of the nutrient guidelines developed by AAFCO, NRC, or FEDIAF, particularly those that use high-fat meats or exclude vegetables.
People who feed home-prepared diets to their dogs often rely on recipes or guidelines they got from books or on the Internet, or on incomplete mixtures of ground meat, bone, organs, and sometimes vegetables that the manufacturers have assured them contain everything their dogs need. But unless the diets have been analyzed and found to meet – at a minimum! – the AAFCO guidelines, they may actually harm the dogs they were meant to nourish, especially when fed exclusively.
All of the above is why, when we begin sharing recipes with you for home-prepared diets, in contrast to many other sources of homemade diet guidelines and recipes, they will be “complete and balanced” diets as per the most recent AAFCO nutrient guidelines. The AAFCO guidelines may not be perfect, but when met, they can protect dogs from nutrient deficiencies that can cause serious disease. We think these guidelines are ignored at your dog’s peril.
Karen Becker, DVM, practices integrative veterinary medicine at the Natural Pet Animal Hospital in Bourbonnais, Illinois. She is also the author of Dr. Becker’s Real Food for Healthy Dogs & Cats, and creator of Dr. Becker’s Bites.
Steve Brown is the founder of Charlee Bear dog treats and Steve’s Real Food for Dogs (but is no longer affiliated with either company), and is author of two valuable books on canine nutrition, Unlocking the Canine Ancestral Diet and See Spot Live Longer. Brown lives in Oregon.
Mary Straus is a retired software engineer with a deep avocation for research in canine nutrition. She lives in the San Francisco Bay area, and shares her discoveries about canine health and optimum nutrition on her website, DogAware.com.