A 2020 Update on Diet-Associated DCM 

May 16 2020

Following the June 2019 update from the FDA on their investigation into canine dilated cardiomyopathy and grain free diets, an eerie silence seemed to befall the issue. In part due to the time it takes for studies to be conducted, in part due to the fluxing nature of news in the modern age, and in part due to the swath of far more pressing concerns that have plagued 2020, concerning surrounding DCM and pet food seemingly fell off the radar. However, now researchers at U.C. Davis School of Veterinary Medicine have published a prospective, observational study on the issue, further supporting the link found by prior retrospective research, the FDA investigation, and reported clinician observations. This study's findings again highlight the need for nutrition experts to take back the stage of the pet food industry, rather than continuing to remain in the backseat to marketing and consumer fads.

The Study

     The study in question is the first prospective study to be published evaluating the role of modern non-traditional diets on the development of DCM, contrasted with the existing retrospective literature. This is significant in that prospective studies allow for a greater control of extraneous factors, providing strength to the findings that is often hard to achieve with the limitations of a retrospective analysis. 

     The study authors defined non-traditional (NTD) diets as "kibble or raw food which is grain-free, includes legumes or potatoes in the ingredient list, or is manufactured by a pet food company with less than $1 billion in global sales for 2018." Traditional diets (TD), to which these were compared were "kibble diets which are grain-inclusive, not including legumes or potatoes in the top 5 ingredients listed, and .. produced by a pet food company with greater than $2 billion in global sales for 2018." Dogs selected for the study had to have a consistent diet history for at least 3 months prior to the study period and have no clinical signs of cardiac disease. The NTDs included brands such as Acana, Orijen, Fromm, The Honest Kitchen, Kirkland Signature, and Taste of the Wild, among others. The TDs included Purina Pro Plan, Purina One, Royal Canin, and Eukanuba. 

     The study subjects totaled at 86, with 43 consuming TDs and 43 consuming NTDs. The groups each contained a roughly 50/50 spread of males and females. Measured parameters included the diet fed, fractional shortening (a cardiovascular measurement of the change in the heart's diameter when contracting), left ventricular diameter measured via echocardiogram, and both whole blood and plasma taurine levels. The findings? Dogs fed NTDs had significantly lower whole blood taurine concentrations compared to dogs fed TDs, but there was no significant difference between the groups in plasma taurine concentrations. Echocardiographic parameters, including left ventricular diameter, and fractional shortening, were significantly more abnormal in the NTD group. 

     The authors conclude: "The current study affirmed our hypothesis and further validates the findings of multiple previous studies and the FDA alert. Grain-free diets, produced by small companies, including legumes within the top 5 ingredients represent a risk for the development of taurine deficiency and echocardiographic abnormalities consistent with DCM in the golden retriever." So where does this leave us?

The Pet Food Industry

     It's no secret among pet professionals that the pet food industry has changed rapidly in the last decade. As dogs have been accepted into our homes from the backyards and made to feel more like family members than lawn ornaments (a good thing!!), consumer focus has shifted to providing pet foods that mirror the appeals of human foods. While the intent is good, the perceptions aren't always accurate. Discerning owner's are drawn to foods that are marketed as fresh, preservative free, by-product free, limited ingredient, organic, holistic, and all-natural. Myths are perpetuated within circles of dog enthusiasts, and online media serves to propagate these myths with ease. The problem arises in that these perceptions are myths. Fresh food hasn't been shown to confer any health benefits when studied alongside kibble. It does spoil more quickly, however, and may be more prone to variation or inconsistency in nutrient quality. Preservatives are safe, and they prevent fats in the food from oxidizing-- a process that occurs naturally and can lead to toxic changes within the food. By-products may be unappealing to us, largely because of culture (cow tongue, anyone?), but they are great sources of essential nutrients, often serves as superior sources of vitamins and minerals when compared to traditional cuts of meat. Terms like 'holistic' are undefined within the realm of pet food regulation and are used with the sole purpose of drawing in a consumer. 

     Unfortunately, this has created a rift between heavily researched, long-standing pet food companies, like Purina and Royal Canin, that continue to utilize by-products and preservatives, and ingredients like corn, that have been demonized despite their digestibility, safety, and nutrient profile, and consumers that believe such traits reduce the quality of a food. Armed with good intentions, but little science, the market has shifted from being more about fads than science, and that can have disastrous results. 

     Companies capitalize on these consumer perceptions. They know that people are willing to spend more on their pets if they believe they're getting the very best for them, and they know that we live in a culture where expensive is equated with quality. This provides them a two-fold advantage-- simply by increasing the price of their product, they're making the product higher quality in the eyes of the consumer. This is without the rigorous testing, research, and quality control that larger companies have.

The Need for Experts

     Nearly everyone is on the same page at this point-- good food is essential for good health. What always ends in contention is the question of what qualifies as "good food." To answer this question, we need to turn away from the market and towards the experts, towards research, and towards scientific evidence. 

     Over 500 veterinarians, nutritionists, food scientists, toxicologists, behaviorists, and engineers work at Nestle Purina. At least three belong to the American College of Veterinary Nutritionists, of which there are less than 100 diplomats. This number is not advertised on their website and may be larger. Over 200 experts are employed at Hill's, including four DACVNs. Royal Canin does not advertise how many experts they employ, but they have a long history of collaborating closely with veterinary professionals and investing extensively in research. Royal Canin employees at least 10 DACVNs. It should be no surprise that their are virtually no cases of diet-associated DCM linked with these diets, particularly when considered against market share. 

     Of the eight brands listed with > 15 reports in the FDA's June 2019 update, there is not a single DACVN employed between all of the companies. Many of the companies claim to work with a team of experts, but only two boast having a nutritionist of any kind (neither a veterinary nutritionist). One company consults with a DACVN. Research, science, and expert opinion matter when it comes to formulating foods, especially when those diets utilize novel ingredients and try to put forward unique formulations. 

The Role of Veterinarians

     The solution to this problem isn't immediate, but it begins with education and an open mind. So many people have been taught things that are very wrong about canine nutrition. They're also been led away from their best source of accurate information on the topic-- their local veterinarian. Contrary to popular opinion, the 8+ years of veterinary curriculum do cover nutrition, and vets are not in the pockets of pet food companies. Many vets can tell stories of clients returning to their office with complaints that the pet store employee down the road said that all of the instructions given by the vet for disease management with nutrition were wrong. How did we get to a place where the opinions of employees at an establishment literally kept in business with the profits generated by the sale of pet foods are valued over the input of trained medical professionals?

     Pet store employees, particularly at small, boutique shops, are trained on how to sell consumers pet food products. While much of this is done under the guise of nutrition education, these employees are taught many of the same pervasive myths mentioned above that certain manufacturers rely on to sell their product. These same shops may receive benefits from recommending certain products over others, or meeting sales quotas within brands. These kinds of relationships are fundamental to successful business, and while they don't necessarily indicate foul play, they should urge caution when considering biases. Even veterinarians may be given incentive to purchase food from manufacturers, in the form of lower buying costs that can be translated to lower client costs and a competitive edge over other retailers. However, the difference arises in that a veterinary practice's primary source of profits is not pet foods. On top of that, veterinarians are educated to be discerning consumers and can better evaluate the quality of products they're offered before passing them on to their clients, who trust them to make those evaluations. Pet store owners rarely have the medical education necessary to make such judgement, and they certainly didn't take an oath to preserve and protect animal health. At the end of the day, most veterinarian's will happily recommend a diet that you can purchase outside of their clinic, and you can rest assured there is no back pocket motive. 

     According to the American College of Veterinary Nutritionists, your general practice veterinarian is the first step in a nutrition consultation, and they should be well equipped with the necessary competencies to guide you in selecting a pet food and developing a feeding regimen tailored to your pet. For more specific concerns, veterinarians can refer clients to the closest boarded nutritionist. 

What You Can Do

     The biggest force in the pet food market is the consumer. Everyone loves their dogs, and right now our dogs need us to be their loudest voice and strongest advocate. As a consumer, you can demand that companies invest less in marketing and more in research. You can stress the importance of a company having experts in charge of their formulation processes, and research to back up their formulas. You can encourage your fellow dog-lovers to do the same, and help educate on marketing vs science. You can have a conversation with your veterinarian about nutrition, and if they aren't comfortable with the topic, encourage them to pursue nutrition CE and open that conversation with more of their clients. Hindsight is 2020. No one knew that the surge of grain-free diets would end with the deaths and illnesses of an unnumbered swath of dogs. But we know now more than ever the importance of leaving nutrition to experts, and 2020 can be the year that drives a change. 

Thanks for reading! Want to connect with veterinarians and fellow pet owners to discuss nutrition, dog food, and canine DCM? Consider joining Diet-Associated Dilated Cardiomyopathy (DCM) in Dogs

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