Since first publishing the article on February 7th, we received questions and perspectives from several AVMA members. This is clearly an important topic, and one that veterinary professionals are passionate about. However, it is also clear that views are very divided. In response to the questions we received and in an effort to shed more light on this complex topic, we updated the article to further clarify the facts initially presented in the article and included additional information to assist readers as they explore this complex topic.
Until more science is available, FDA will end public updates on potential link between certain diets and canine dilated cardiomyopathy
Agency says the adverse events reported, by themselves, do not provide sufficient data to establish a causal relationship
Updated February 11, 2023
The Food and Drug Administration announced on Dec. 23, 2022, that the agency plans to end routine updates on the investigation of case reports of nonhereditary canine dilated cardiomyopathy and of certain dog foods and ingredients.
“While adverse event numbers can be a potential signal of an issue with an FDA regulated product, by themselves, they do not supply sufficient data to establish a causal relationship with reported product(s). FDA continues to encourage research and collaboration by academia, veterinarians, and industry,” the agency stated.
In July 2018, the FDA announced that its Center for Veterinary Medicine and the Veterinary Laboratory Investigation and Response Network had begun investigating reports of DCM in dogs eating certain pet foods, many labeled as “grain free,” which contained a high proportion of peas, lentils, other legume seeds or pulses, and potatoes in various forms as main ingredients. The adverse event reports received by FDA CVM suggested that DCM was occurring in breeds not typically genetically prone to the disease. By June 2019 the agency had concluded that the potential association between diet and DCM in dogs was a complex scientific issue likely to involve multiple factors. Scientists were also looking more closely at pulse ingredients, rather than simply the presence or absence of grains, in canine diets.
In September 2020, Kansas State University held a virtual scientific forum to examine the potential causes of non-hereditary DCM in dogs. The event provided a forum for scientists with research into DCM to share information, collaborate, and discuss many different ― and sometimes conflicting ― theories on the condition. Stakeholders from academia, industry, and veterinary medicine touched on different facets of the issue, including nutrition, cardiology, and toxicology. The FDA published a Q&A after the forum that stated, “emerging science appears to indicate that non-hereditary forms of DCM occur in dogs as a complex medical condition that may be affected by multiple factors such as genetics, underlying medical conditions, and diet. Aspects of diet that may interact with genetics and underlying medical conditions may include nutritional makeup of the ingredients and how dogs digest them, ingredient sourcing, processing, formulation, and/or feeding practices.” Since July 2018, a substantive number of peer-reviewed research papers have been published on the topic. However, a specific cause of non-heredity DCM in dogs still has not been identified.
Dr. Steven Rosenthal is a veterinary cardiologist and the co-founder and co–chief medical officer of Chesapeake Veterinary Cardiology Associates, a veterinary cardiology practice based in the mid-Atlantic states. CVCA has provided records for some DCM cases to the Veterinary Laboratory Investigation and Response Network, including imaging studies of the animals’ hearts, comprehensive dietary histories, diagnostic and treatment records, and case outcomes.
Dr. Rosenthal explained that diet formulations often change, which makes evaluating patients for diet-associated DCM a “constant battle with this moving target.”
“From my personal impression, I believe the incidence of disease related to DCM has reduced over the past couple of years, and there’s a number of reasons why that may be the case,” Dr. Rosenthal said.
He suggested reasons could include changes in the diets themselves, increased public awareness, and reduced frequency of feeding diets associated with this disorder.
From Jan. 1, 2014, through Nov. 1, 2022, the FDA received 1,382 reports of DCM in dogs, with the majority of reports received between 2018 and 2020. More recently, reports to FDA CVM have been less frequent (255 received between Aug. 1, 2020, and Nov. 1, 2022). The FDA works with the Centers for Disease Control and Prevention and state boards of health to collect and track cases of foodborne disease in humans. Unfortunately, there is no equivalent for pets, which makes it difficult to accurately evaluate the scope of disease, particularly when statistics on the background rate of non-hereditary DCM in dogs are not available. Reporting to the FDA is also voluntary, and may not reflect the true incidence of the condition in the canine population.
Dr. Rosenthal recommended that pet owners refer to the nutrition guidelines from the World Small Animal Veterinary Association’s Global Nutrition Committee to make sure their dogs and cats are on the correct diet.
“A diet should be individualized per pet by age and by health status,” Dr. Rosenthal said. “A vet can help advise through that and working with a veterinary nutritionist is helpful to help choose or formulate a diet best for the specific pet’s needs.”