When is a Test Not a Test?

A certain bit of advice is currently circulating on social media at an ever-accelerating rate, and is spreading to veterinarians and other pet professionals. And it is one of the biggest pieces of misleading information ever told to consumers, about any product that I am aware of. Consumers are taking it as gospel, and sharing it with friends and family. If it not already considered “viral,” it soon will be.

Of course I am not surprised when any company uses words to their advantage when describing the quality, efficacy, or safety of their products. I even get that they may “stretch the truth,” to cast their products and themselves in the best light possible.

But what about when organizations of educated animal health professionals spread this misleading information? And then their influence further aids the spread of the misinformation even faster, as it now has the endorsement of an organization of professionals?

Of course I am speaking of the advice being given to dog owners to only feed products that have been tested in an AAFCO (American Association of Feed Control Officials) feeding trial. This advice is being given by the World Small Animal Veterinary Association, researchers at leading veterinary colleges, veterinarians, pet industry employees, and now, dedicated owners who are (sadly) affected by the taurine responsive dilated cardiomyopathy problem. In fact you will actually see or hear statements made that if a food has not passed a feeding trial, you should not consider it.

You are probably wondering what I am thinking – how could testing a food be bad? In fact, shouldn’t every food be tested? Once it has met the calculated or formulation standards on paper, shouldn’t we be sure that it actually is something our dogs will thrive on?

I absolutely believe that commercial foods for dogs and cats should be carefully formulated according to our best knowledge, and then be thoroughly tested before being sold to the general public. It’s the emphasis on AAFCO feeding trials that I strongly disagree with. And I believe if my veterinary colleagues actually took a moment to understand what an AAFCO feeding trial’s requirements are, they would be equally offended. The graphic below explains the key components of an AAFCO feeding trial. (I am happy to provide documentation verifying this should you desire).

Yes, that’s right. Only six dogs, usually laboratory Beagles, surviving six months on a food, with minimal health testing, passes an AAFCO feeding trial. (Note: the study may start with eight dogs, allowing two to drop out for various reasons). How is this a valid comparison to the dogs that we share our lives with? The varying breeds, activity levels, ages, health challenges? What about working dogs, from police and military dogs to service dogs? And do just four laboratory parameters accurately reflect body function? I’m sure the criteria that they not lose weight is not a factor, as the dogs can be free fed, meaning they always have access to food. As a veterinarian, I recommend meal feeding for the vast majority of my patients, so allowing free feeding is yet another way the AAFCO feeding trial does not apply to my patients.

Let’s look at the four blood test criteria checked in an AAFCO feeding trial. The first, hematocrit, is a measurement of red blood cells, as a percentage of the volume of whole blood. The second, hemoglobin, is the molecule in the blood which carries oxygen. Hemglobin production is dependent on adequate iron intake. The third, albumin, is a protein found in blood. Low levels may indicate malnutrition, liver disease, maldigestion problems, inflammatory disease, or other issues. Finally, alkaline phosphatase is an enzyme which can reflect liver or bone problems. Per the rules for a feeding trial, these tests are run at the end of the six month trial.

In comparison, when I as a veterinarian evaluate a dog’s health, I look at many more than four parameters. Below is an example from my own dog, a healthy raw fed female Australian Shepherd, 16 months old at the time. Note: I have highlighted the parameters checked in the AAFCO feeding trials in the report.

Notice how much more information is contained in this CBC/blood chemistry test! I was doing this test to obtain baseline data, as I feed a home prepared raw diet. I do this test at least once a year on my own dogs, and in some cases more often or in conjunction with other testing. Serial samples allow me to see trends in values, which could indicate a problem. So why does AAFCO feel that testing four blood parameters once after feeding a diet for six months is “proof” that a food is nutritionally adequate for a dog’s whole life? By using the full blood chemistry as shown above, I can pick up on changes in kidney function, liver function, or pancreatic problems that AAFCO testing would miss. A complete blood count (CBC) tells all the details on red or white blood cell production or deficiency, and more. Nutritional deficiencies or toxicities take time to develop, in some cases years. Using the most sensitive tests to pick up on problems only makes sense, to pick up the earliest clues that something is going wrong.

Why doesn’t AAFCO require more complete testing protocols, which are readily and inexpensively available at laboratories and with in house analyzers? Why do trials only last six months? Why don’t they use dogs that more closely mirror the dogs we own? Those would be questions for them, but there are companies doing more thorough testing of their products, and sharing their results. One such company is Just Food For Dogs (JFFD). I have no affiliation with them at all, have not used their products, and receive no compensation of any type from them. I am sharing this information as an example and because I respect their efforts to go above and beyond AAFCO requirements, and to contribute to the scientific knowledge of dog nutrition.

A summary of the JFFD study is available here (PDF). It’s important to recognize that the JFFD study used over 3 times as many dogs as an AAFCO trial, ran twice as long, and ran three full CBC/chemistry profiles. Dogs of varying ages and sizes were used. Numerous differences in blood test values were found, some of which may indicate better body function when dogs were fed whole foods versus kibble. Below is a question and answer video from Dr. John Tegzes, a professor at the Western University School of Veterinary Medicine, which explains more about the study.

In a perfect world, the foods we feed our dogs would undergo lifetime, real world testing, prior to being released to the public. Instead, today we have minimal screening prior to product release, and that lifetime real world testing begins when the product starts to sell. Is that OK for your dog? As a veterinarian I believe it’s time we move forward. It’s time to stop looking at AAFCO feeding trials as a “gold standard” for evaluating a pet food, and see them for the antiquated, inadequate assessments that they are.

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