Cases of canine dilated cardiomyopathy (DCM) did not increase significantly from 2000 to 2019 as sales of grain-free pet food were soaring, at least from 2011 to 2019, at a rate of 500%. That’s the conclusion of a peer-reviewed study by BSM Partners released on March 17, 2022, and published in the journal “Frontiers of Animal Science.”
“Based on the data we received from veterinary cardiologists across the U.S., we did not observe a significant increase in DCM incidence rate over time, which included the recent period when grain-free pet food sales grew exponentially,” said Stephanie Clark, Ph.D., CVT, PAS, CFS, Dpl. ACAS of BSM Partners, an article co-author and a board-certified companion animal nutritionist, in a press release. “The existing scientific literature indicates that nutritional factors can lead to the development of DCM, but we did not find a correlation in the DCM incidence rate to grain-free pet food sales.”
After all the hype, anxiety and tension – not to mention lost sales – resulting from the Food and Drug Administration’s (FDA) investigation into a potential link between DCM cases and grain-free pet food, starting in 2018, this finding may tempt some people in the pet food industry to respond with, “I told you so.” That would be understandable. But I think a more productive response would be to look for lessons learned (by all involved) and other research needed to try and get to the bottom of this and other issues.
What the data shows
Another of the study’s co-authors, Stacey Leach, DVM, DACVM, chief of cardiology and associate teaching professor of cardiology at the University of Missouri’s Veterinary Health Center, commented that the research was unique because it examined only cases of DCM diagnosed by veterinary cardiologists. The researchers received information on more than 68,000 total canine cardiology cases from veterinary cardiology referral hospitals, diagnosed between 2000 and 2019. The average incidence rate of DCM was 3.9% (ranging from 2.53-5.65%).
The assumption is that, if grain-free pet food did indeed cause or directly contribute to DCM, the incidence rate of the disease would be much higher given the category’s huge sales and consumption by dogs, especially in the last half of the study period. Yet the data did not show that at all.
Ongoing research is key
This latest research came shortly after I was contacted by an Associated Press (AP) reporter who was working on an article about the current state of the DCM investigation. My original response at the time was that the investigation seemed essentially over, at least for FDA. The agency apparently has completely back-burnered it since September 2020, when it (finally) acknowledged that DCM is a “complex medical condition that may be affected by the interplay of multiple factors such as genetics, underlying medical conditions and diet.” And that was the last word on it from FDA.
However, that doesn’t mean the investigation, and fallout from it, are over for everyone. The reporter said she had seen new research from veterinarians and veterinary cardiologists, including some who had originally raised the alarm with FDA in 2018. And the occasional article about the purported link between DCM and grain-free pet food still appears on news sites, TV networks and in newspapers, which seems to perpetuate the confusion and concerns still experienced by many veterinarians, pet retailers and, especially, pet owners.
That’s one reason I believe ongoing research—by industry partners like BSM as well as veterinarians—is a good thing. The more scientifically backed information available, the more it calms the anst and, ideally, even the tensions among various parties involved. When I talked to the AP reporter, I remarked that a truly unfortunately outcome of this entire situation, besides the anxiety, is the friction, even animosity, that developed among veterinarians, retailers, and people and companies in the pet food industry. Any research or other information that can bring these factions together, or at least engaging in a constructive discussion, would be helpful.
We need more pet food research
Further research would bring other key information to light. When the DCM investigation began, the pet food industry arguably was not in a strong position to refute the assumptions behind it, in that there was little research showing that ingredients common in grain-free pet foods, like legumes, are safe and healthy. Fortunately, that research is now happening (by BSM and University of Guelph, for example), but a lack of research is an ongoing problem in pet food, especially when it comes to newer ingredients.
In fact, some pet food experts have expressed concern that the industry has opened itself to further issues or scrutiny with recent trends, like products with ancient grains (a direct response to the DCM/grain-free investigation), that have only so much research behind them.
Let’s figure out how to develop more research. If you would like to participate in that discussion and effort, consider checking out a roundtable session on the topic on May 4 at Petfood Forum 2022. (An on-demand version of this and other sessions will be available to anyone not able to travel to Kansas City.)
