A new study looking at canine dilated cardiomyopathy (DCM) and a possible link to grain-free pet food corroborates what many in the industry have been saying since July 2018, when the Food and Drug Administration (FDA) first announced its investigation into this matter: There is no clear or confirmed link.
Yet there is also no cause for celebration or satisfaction – not only because, as the study authors emphasized, much more research is still needed, but also because this investigation and situation have created a huge source of anxiety, confusion and frustration for veterinarians, pet retailers and especially dog owners, in addition to pet food companies and other industry members. Perhaps unnecessarily and still with no real resolution, nearly two years later. What was the point?
No definitive relationship between implicated diets and DCM
The study, published June 15 in the Journal of Animal Science and conducted by veterinarians, veterinary cardiologists and animal nutritionists at consultancy BSM Partners, was a literature review comprising more than 150 previous studies on canine nutrition and its relationship to DCM.
The first paragraph of the authors’ conclusion is worth quoting in full:
Recently, a correlation between diets with specific characteristics, such as, but not limited to, containing legumes, grain-free, novel protein sources and ingredients, and smaller manufactured brands, to DCM has come under scrutiny by academic researchers and FDA. The use of the acronym “BEG” and its association with DCM are without merit because there is no definitive evidence in the literature. At this time, information distributed to the veterinary community and the general public has been abbreviated synopses of case studies, with multiple variables and treatments, incomplete medical information and conflicting medical data and opinions from veterinary nutrition influencers. Also, in past literature, sampling bias, overrepresentation of subgroups and confounding variables in the data weaken this hypothesis. Additionally, based on current literature, the incidence of DCM in the overall dog population is estimated to be between 0.5% and 1.3% in the United States. However, the FDA case numbers (560 dogs) are well below the estimated prevalence. Therefore, it is impossible to draw any definitive conclusions, in these cases, linking specific diets or specific ingredients to DCM.
In summary, no scientific research provides proof of a link between DCM and specific types of pet food, or even the “BEG” (boutique, exotic protein and grain free) term invented by some veterinarians; the case studies, data and other information related to the DCM cases in the FDA investigation are not at all complete and, in some cases, even conflict; and previous studies related to DCM have research problems that “weaken this hypothesis” of a correlation between DCM and specific types of pet foods.
The authors also pointed to the relative prevalence of DCM in the dog population, which other industry experts have discussed, along with DCM’s being a “multifactorial medical condition with many proven etiologies and potential causes.”
Next steps: more research needed
Since the beginning of this complicated, controversial DCM situation, nearly all parties and factions involved have agreed on one thing: More research is a must. The new study’s authors recommended further studies investigating diet plus infection, metabolism and genetic involvement – and better data. “In hopes of better understanding a potential correlation with diets to DCM, more objective data need to be collected and analyzed, without sampling bias and confounding factors,” they wrote.
Even FDA, though nearly silent on its DCM investigation to date in 2020, has said the investigation is ongoing – while also declining to comment on this new study. “FDA does not typically comment on specific studies, but evaluates them as part of the body of evidence to further our understanding about a particular issue and assist in our mission to protect public health,” a statement from the agency reads. “We are continuing to investigate cases of DCM reported to the agency and will communicate publicly about any significant developments.”
Negative consequences for so many people
Significantly, more than 500 dogs have suffered from DCM over the past two years, some even dying, leaving their owners understandably heartbroken and likely angry; and all owners whose dogs have been diagnosed with DCM in that period have endured serious worry, frustration and probably large veterinary bills.
Unfortunately, they – and everyone else – are nowhere closer to having answers to why the dogs developed DCM. Meanwhile, confusion and anxiety have simmered among not only these owners but also pet retailers, veterinarians and pet food professionals, and companies, brands, ingredient suppliers and farmers have lost considerable business, leading to layoffs even before the COVID-19 pandemic ravaged the economy.
Perhaps the answer to my own question – the point of the FDA investigation in the first place, on up to today – is the ongoing need for more research, not only on DCM and diet but also on so many other aspects of pet nutrition and ingredients. Yet how FDA handled the investigation and the situation overall has had significant, negative consequences, and that indeed seems pointless.