Good Canine Nutrition Demands Good Science

Good Canine Nutrition Demands Good Science

by Kim Skibbe, DVM

An unfortunate evolution in mainstream dog food

Our knowledge of canine nutrition has grown by leaps and bounds over the last two decades. Our ability to treat and in some cases manage or even prevent disease through research-backed advances in nutrition has done wonders to improve the quality of life for so many of our dogs. Unfortunately, we have seen equal “advances” in non-research-backed, market-driven canine nutrition, the primary aim of which is to appeal to humans based on their own preconceived notions of nutrition, rather than on what has been scientifically proven to be of most benefit to our dogs.

The grain-free movement is a perfect example

There is no overall documented medical benefit to grain-free diets and there is little to no study as to what effects grain alternatives, particularly legumes, have when fed to dogs. This general trend toward market-driven canine nutrition has effectively chosen to ignore more than 70 years of canine nutrition science and research in favor of new, poorly studied ingredients and formulations that are now implicated in causing significant damage, and in some cases, death, in our dogs. This is evidenced by the recent increase in Nutritionally Mediated Dilated Cardiomyopathy (NM-DCM) – a devastating and deadly heart disease.

Positive outcomes require a return to science

Without a full team of experts, extensive study, nutrient and digestibility analyses, feeding trials and so much more, we simply cannot expect to understand how new ingredients, especially in large concentrations, will affect our pets, either positively or negatively. As our understanding of pet nutrition advances, the addition of new ingredients is both expected and welcomed, as are incremental changes to improve canine diets based on new knowledge – but they must be adequately studied and tested over prolonged periods of time before we allow them to become part of mainstream pet nutrition. We owe it to our dogs, who have given us so much, to ensure the food we feed them has undergone extensive research and testing.

The cost of diseases, such as NM-DCM, is simply too high a price for dogs and their devastated owners to pay.

Heart disease is on the rise and nutrition is strongly implicated

Now that novel diets have grown in popularity, we are experiencing a most unpleasant surprise. NM-DCM correlated with some diets is a preventable disease that can remain hidden until it is in its late stages. The cost to families for diagnosis and treatment of a dog is thousands of dollars. The cost to the dog and its family may be a dog’s life.

A possible correlation between these unusual diets and the recent rise in DCM was noticed in 2017 and 2018 at veterinary cardiology clinics. There were likely previous cases, but perhaps not enough to see a correlation. Several actions were taken. Studies were proposed, the FDA was alerted, word went out to the veterinary community, and the public started becoming aware. Quality studies are not expedient, meaning they require specific methodologies and case recording. Even after all data is collected, the process of careful peer review, editing, and re-editing takes months at minimum and often more than a year.

Because of the serious nature and alarming increase of nutritional DCM in dogs not genetically predisposed to this disease, cardiologists knew that waiting for the peer-review process would mean more lives would be lost to DCM.

Veterinary research and nutrition communities rose to action

Dr. Lisa Freeman, a board-certified veterinary nutritionist with a research emphasis on nutritional effects of heart disease, wrote about the concern in the Tufts University veterinary school nutrition blog in June 2018. Dr. Freeman and several veterinary cardiologists also collaborated on a commentary placed in the Journal of American Veterinary Medical Association (JAVMA) – one of the most widely read journals by veterinarians in the United States and a great place to reach general practicing veterinarians.

A similar commentary was published by JAVMA in 2001, when veterinary toxicologists identified multiple cases of renal failure in dogs after ingesting grapes or raisins. Then, like now, peer review took time. In fact, even after multiple case studies and 18 years later, the mechanism is still unknown as to why grapes sometimes cause renal failure in dogs. Yet, it has become common knowledge among veterinarians and pet owners that we should avoid feeding dogs grapes and raisins until this is better understood. There are even guidelines in place for veterinarians to initiate treatment in the event of ingestion.

In both the 2001 potential grape toxicity commentary and the 2018 NM-DCM commentary, the desire was to reach veterinarians with this important information and save lives.

The JAVMA editorial linked above, “Diet-associated dilated cardiomyopathy in dogs: what do we know?” appeared online in November 2018. Since that time, two peer-reviewed studies have been published and we have information from hundreds of cases collected via the FDA’s adverse event reporting system. More studies are under way at several universities and cardiology practices. Each piece of information provides further evidence for the correlation, and each piece of information is reaching the public and veterinary practices to help identify, treat, or prevent more cases of NM-DCM.

Dissenting voices do not change what is known about NM-DCM

One individual and pet food producer (Daniel Schulof) complained about the JAVMA editorial not being peer-reviewed, which is nonsensical as the editorial was never presented as peer reviewed. As a commentary, like the one about grape and raisin toxicity, it was presented as important information to share with veterinary colleagues. Schulof asked for a retraction of the commentary and claimed biases. In the past, some of the researchers in the commentary have received funding from pet food companies. This is not unusual as corporate funding is a mainstay of animal research. Schulof goes on to dismiss even the Morris Animal Foundation for conflict of interest.

It appears most of Schulof’s concerns arise from a lack of familiarity with science and research methods. Again, it is senseless to complain that a non-peer-reviewed commentary was not peer reviewed. The commentary was not presented in any way as research or a review article. The respective formats are entirely different.

Schulof’s comments on the two peer-reviewed and published studies on nutritionally-mediated DCM are similarly misguided.

The Kaplan, Stern et al. study published in PLOS ONE was an observational study following the progress of dogs diagnosed with suspected NM-DCM. Schulof characterizes the fact that the researchers did not collect and analyze the dogs’ diets as a “methodological irregularity.” It is an inherent constraint of clinical research that researchers only have access to data they decided to collect ahead of time. Further, every scientific study has limitations, which is why new studies are always being conducted – to build on previous ones and address remaining gaps in knowledge. With regard to food testing as it relates to NM-DCM, the FDA has collected and tested food samples for both deficiencies and toxins.

As for the Adin et al. study, Schulof claims it is suspicious that the authors’ abstract presented at a conference was not identical to the final paper that was published. Abstracts must be submitted to conferences months ahead of time and frequently do not duplicate the final version of a study. A large part of the reason for presenting work at conferences is to get feedback and suggestions from other scientists. It is a normal part of the scientific process to make changes between presenting a study at a conference and publishing a paper.

Schulof says DCM deserves “real science.” The veterinary research and nutrition communities agree! And to date, real science is being carried out by the very professionals Schulof seeks to disparage and distract with his retraction letters and FOIA requests. He doesn’t offer a useful solution. He is neither a nutritionist nor veterinarian, and every action he is taking is to interfere with science, not support it.

It is always fair to look at conflicts of interest, which is precisely why ethical researchers report those conflicts. Funding, especially past funding, does not invalidate discovery, data or expertise! If we stretch concern for conflict so far that we cannot accept information from professionals simply because they are employed by universities that once received corporate funding, we won’t have many experts left to whom we can listen. Even if there were an independently wealthy veterinary cardiologist who has never taken a salary, I expect Schulof could find conflict in where this person’s wealth originated, just as he deemed the Morris Animal Foundation in conflict because Dr. Mark Morris started Hill’s Pet food. While Schulof dismisses experts based on such connections, his own financial motivation is clear. He states in his letter that “my company has suffered significant financial damage.”

Who is REALLY paying for research into NM-DCM?

    1. Dog owners whose dogs are diagnosed with NM-DCM have each spent thousands of dollars. Some of their cases have been used in peer-reviewed studies and the FDA investigation.
    2. Taxpayers are indirectly funding this research and discovery through the FDA investigation.
    3. Donors such as the AKC Health Foundation are funding more studies.


BEG actually does represent the risks of certain diets

Schulof and others have also complained about the “BEG” diet acronym coined by Dr. Freeman. However, what we are seeing so far is that this acronym is a fairly useful designation. Each letter represents a possible risk factor. Let’s talk about that a bit more.

B is for Boutique: It’s fair to say this does not have a definition. However, a reasonable working definition for Boutique is: 1) Companies that do not have a full team of experts, including board-certified veterinary nutritionists, PhD animal nutritionists, food scientists, toxicologists, microbiologists, veterinarians, and chemists. 2) Companies that may not be performing adequate research for the diet formulations they produce.

Companies that do have adequate scientific staffing and research centers and do perform multiple feeding trials and publish research fit into the category that veterinarians identify as meeting the global nutrition guidelines set by the World Small Animal Veterinary Association (WSAVA). See the infographic at the end of this article.

Companies that meet WSAVA nutrition guidelines currently have no significant correlation with NM-DCM. These companies also happen to be very large, so if there were multiple cases occurring on their diets, it simply could not be overlooked. Brands that meet WSAVA guidelines are commonly fed to breeding and performance dogs, who often have echocardiograms as part of their health checks. In my practice, 99% of my clients feed a diet from one of these well-researched brands. And their dogs simply are not collapsing at age 1 or 5 or 9, or being rushed to the cardiologist to be diagnosed with DCM. This tragedy IS happening with dogs eating boutique diets, and the trend is alarming.

Bottom line: Science matters! When manufacturers start using ingredients for which nutrient analyses and outcomes have not been deeply studied and published, they need to conduct that research internally. They need to be aware of fiber types and digestibility and most especially bioavailability of the final diet. They need experts to determine exactly WHAT parameters to look for before their diets go on the market. Boutique dog food companies are doing the equivalent of using one or two engineers to build a vehicle, then convincing the public that their components are so good there is no need for test drives or crash testing. What this ultimately means is your dog is their test subject!

E is for Exotic: It is my understanding that original nutrient needs in dogs were determined using common meats, meals, and by-products. Thus, when novel, or exotic ingredients (fish, lamb, kangaroo, etc.) are used, it is not known if the ingredient’s theoretical ‘laboratory’ analysis will work out accordingly in a real dog. Again, similar to adding legumes to dog food, manufacturers who use exotic ingredients need the experience to ask the right questions – and research to find the answers.

While exotic ingredients can sometimes be safely used, they present a risk factor because they are less understood. Some bloggers, and even a nutritionist who does not like the BEG designation (Ryan Yamka), have either misused or misunderstood the FDA report when suggesting that exotic ingredients are not a significant problem. Just to use kangaroo (exotic) vs. chicken (common) as an example, here is how it works out compared to market share. If kangaroo were not disproportionately linked to NM-DCM, it would be less than 1% of reported cases[1].

G is for Grain-Free: Grain-free diets often contain legumes or potatoes. In the FDA’s most recent report, 91% of diets reported for correlation with NM-DCM fell into this category. With these diets representing just under 50% of the market, grain-free food is obviously a risk factor.

Some of the most commonly reported diets associated with DCM have all three of the BEG risk factors. You might call these diets the perfect storm of BEG. The fundamental problem is of course the component that makes a company boutique. It is possible to produce foods without grains and/or with exotic ingredients; however, boutique companies magnify the risk in their diets when they produce unusual formulas without research, testing, and scientific teams to determine outcomes.

So we see where the “bad science” really exists. It is not in the research about NM-DCM but rather in the formulation and marketing of some dog foods. Ironically, people complaining about the word “boutique” not having a legal definition tend to use meaningless terms like “super premium,” “high-end,” “natural,” and “high quality” – when their diets have no actual science to back such claims.

I expect most people who started a pet food company, manage or work for a pet food company, or sell pet food have done so with the best of intentions. Schulof, for example, appears to be passionate about his ideas on canine health and nutrition. In light of what is happening, I ask that he and other boutique pet food company owners take a more serious look at the evidence and deep complexities of canine nutrition. Marketing a food without background research and necessary expertise is irresponsible, no matter how good or noble the original intentions.

Anyone who does not understand the devastation to families, please read some of the owner case report stories collected in our facebook group. You will find that many, if not most of these dogs appeared and acted completely normal, happy, and healthy until the day they collapsed, and in some tragic cases, died. In addition to owner case reports, we have gathered all relevant research into the group’s “learning units” so you can stay up to date. The moderating team of this group includes seven veterinarians. We also have members that are cardiologists and nutritionists to help answer questions.

What can we do as dog lovers and pet food buyers?

We need to put our money where our mouth is and change what the market demands, and thereby change what manufacturers produce. Veterinarians can and should lead this charge by recommending foods to our clients that meet WSAVA nutrition guidelines. We need to arm pet owners with the knowledge they need to walk away from flashy marketing tactics and misdirection from pet food retailers. Pet health is a team effort. Nutrition is no exception. With veterinarians recommending and dog owners purchasing foods backed by years of research and testing, we can demonstrate where our priorities lie when it comes to feeding our dogs.

For all of us, investing in companies that regularly conduct research and perform extensive and long-term feeding trials will demonstrate to manufacturers that we value science-backed nutrition over gimmicky language and nutritional fads. The only way we can change market-driven pet nutrition is to drive the market in a different direction – one that points to science and testing.

We also need to make it clear that we expect these companies to hold themselves accountable. To continue to produce and sell diets that have been implicated in causing heart disease and death speaks directly to profit – not passion for dogs and nutrition. Evidence continues to mount that there is an association between these diets and the development of NM-DCM, yet they continue to be manufactured, sold, and aggressively marketed to pet owners. This must stop. These diets must be recalled.

Attention must also be paid to dogs and owners who have already suffered loss and continue to struggle with the destructive effects of NM-DCM. Implicated companies must accept responsibility. Owners must be compensated for medical expenses incurred in the diagnosis and treatment of the disease. I believe we can all agree that harm was not the intent in manufacturing and selling these diets, but harm is the result. Companies truly dedicated to the welfare and health of dogs will take corrective action by embracing science and nutritional research, thereby eliminating the effects of neglecting science in the first place.

Here’s why good canine nutrition demands good science

The infographic below illustrates the fundamental questions from the WSAVA Global Nutrition Committee’s recommendations for selecting pet foods. Preferred answers from dog food manufacturers are followed by answers that are less than desirable for producing optimal diets based on nutrition expertise and decades of research and testing.


[1]Sales estimated from and Passport/Euromonitor; actual estimates of kangaroo sales are well below 1%.