Poll: Grain-Free Diets and Dilated Cardiomyopathy
There has been a lot of confusion, misinformation and conversation in the past year about the risk of heart disease in dogs due to being fed grain-free diets.
“Dilated cardiomyopathy (DCM) is a disease of the heart muscle characterized by heart enlargement resulting in improper cardiac function,” says Kara M. Burns, editor-in-chief of Today’s Veterinary Nurse and author of an article examining the relationship between grain-free diets and dilated cardiomyopathy that will be published in the Winter 2020 issue of TVN. “Often seen in DCM cases are abnormal heart rhythms, congestive heart failure, and sometimes even sudden death,” Burns reports.
In the past couple of years, veterinary cardiologists have been reporting increased rates of DCM in dogs – in the breeds with a genetic predisposition for DCM (typically large and giant breeds — Doberman Pinscher, boxer, Irish wolfhound, and Great Dane — and cocker spaniels), as well as in small dog breeds not usually connected with DCM. It’s been theorized that in dogs with no genetic predisposition for DCM, the disease might be caused by the dogs eating boutique or grain-free diets. “What has also been documented,” says Burns, “is that both the typical and atypical breeds were more likely to be eating boutique or grain-free diets, and diets with exotic ingredients – kangaroo, lentils, duck, pea, fava bean, tapioca, salmon, lamb, barley, bison, venison, and chickpeas. This is further associated when improvement in the dogs’ condition is seen upon diet change.”
Further muddying the waters is whether the lack of amino acid taurine in grain-free pet foods plays a role; as of now, it is unclear whether taurine deficiency is a cause of DCM. In fact, many of the affected dogs have normal taurine levels, and giving taurine is unlikely to prevent DCM unless the dog has taurine deficiency.
What’s worse, says Burns, pet owners “are often getting their information from non-veterinary personnel or from the internet.” Burns emphasizes: “To date, no credible evidence has been found showing grain-free diets are better for pets, nor do any nutritional foundations support this claim.”
The Research Continues
To date, the U.S. Food and Drug Administration (FDA) Center for Veterinary Medicine has not established why certain diets may be associated with the development of DCM in dogs not predisposed to DCM. The FDA, veterinary nutritionists and veterinary cardiologists are continuing the research.
It can be difficult to create a sophisticated poll on Facebook — questions must be designed so that respondents can “vote” with a “yes” or “no” response — and this is a complex issue. Some pet owners and veterinary professionals are unaware of the FDA research or completely doubt it; some think DCM is caused only by grain-free diets; some think it’s only related to taurine deficiency. To understand the level of understanding of our Facebook fans and readers — and to help dispel some misunderstandings related to DCM and grain-free diets — we created a poll that asked: Do you understand the relationship between grain-free diets and dilated cardiomyopathy? Nearly 600 people took the poll; 69% answered “yes”; 31% responded “no.”
Do you understand the relationship between grain-free diets and dilated cardiomyopathy?
One respondent who answered “yes” makes this excellent point: “It may be difficult to answer this question as there is a relationship to some grain-free diets and some dogs getting DCM but not all grain-free (Purina Derm naturals has no cases and a different ingredient profile list that is seen in listed diets). Researchers are still investigating the exact cause. It might be better to ask, ‘Do you understand the concerns with those diets listed as grain-free, with limited number, and rare sources of ingredients, and DCM?’”
Another respondent correctly points out that we do not yet know what is causing this disease in DCM in some dogs: “That’s a loaded question because no one does. That’s why the study is ongoing.”
The FDA recently issued an update to its investigation into the potential connection between certain diets and DCM in dogs. (While the FDA has received reports of cats with DCM, the low number of reports — only 10 since January 2014 — has led the FDA to focus on cases in dogs only.) As Burns details in her article, the agency is particularly targeting diets that list peas, lentils, other legume seeds and potatoes within the first 10 ingredients on the label.
Burns concludes her article by noting that “the growing grain-free category of the expanding pet food market is perpetuating the misperception that grain is bad for pets.”
Still, misperceptions and confusion persist. As one respondent said: “Personally, I need a hell of a lot more evidence before I 100% believe this. I am not saying it isn’t possible and shouldn’t be explored, but right now, I am not 100% convinced.”
Visit the Nutrition Archives of Today’s Veterinary Nurse.