Grain-Free Food Not Cause of Dilated Cardiomyopathy (DCM)
In the realm of canine health, Dilated Cardiomyopathy (DCM) has long been understood primarily as a genetic affliction. Certain dog breeds have historically shown a predisposition to this condition, known as primary DCM (Dukes-McEwan et al., 2003; Meurs, 2003; Leach et al., 2022). This predisposition is particularly noted in breeds such as Doberman Pinschers (Wess et al., 2010; Beier et al., 2015), Irish Wolfhounds (Vollmar et al., 2013; Vollmar et al., 2019), Great Danes American Cocker Spaniels, English Bulldogs, Golden Retrievers (Belanger et al., 2005), Newfoundlands (Backus et al., 2003; Fascetti et al., 2003; Backus et al., 2006), Saint Bernards, Portuguese Water Dogs (Sleeper et al., 2002), and Standard and Giant Schnauzers (Harmon et al., 2017). as documented over years of research by experts like Dukes-McEwan et al., Meurs, and Leach, among others.
While genetic factors have been at the forefront, recent studies have shifted focus to potential dietary triggers — specifically, diets rich in pulses, potatoes, and sweet potatoes, often categorized as “non-traditional” diets. This shift in focus was inspired by a series of publications from Kaplan, Ontiveros, Freid, Walker, Freeman, Owens, and Quilliam spanning 2018 to 2023 (Kaplan et al., 2018; Ontiveros et al., 2019; Freid et al., 2021; Walker et al., 2021; Freeman et al., 2022; Owens et al., 2023; Quilliam et al., 2023). However, it’s crucial to note that there’s a counterpoint of research, including studies by Donadelli, Pezzali, Cavanaugh, Reilly, and Singh, showing no detrimental impact on cardiac function from these diets (Donadelli et al., 2020; Pezzali et al., 2020; Cavanaugh et al., 2021; Reilly et al., 2021; Singh et al., 2023).
The discourse on this topic isn’t without its complications. The body of research, though growing, has certain limitations, as outlined by McCauley and others in 2020. These include a lack of control for specific diet parameters, such as the exact quantities of pulses, such as peas, fava beans, chickpeas and lentils, or potatoes, uncontrolled variables in observational studies, and inconsistencies in factors like breed predisposition, supplement use, and sample sizes.
The United States Food and Drug Administration (FDA) has also entered the discussion, prompted by reports of rising cases of suspected diet-associated DCM. They initiated investigations into the potential correlation between certain diets and DCM (1). However, despite a surge in grain-free pet food sales (up by 500% from 2011 to 2019, as reported by Quest et al.), the incidence rate of DCM diagnoses in dogs remains relatively unchanged in veterinary hospitals across the United States.
Amidst this complex scenario, a prospective study was designed with specific objectives: to monitor changes in echocardiographic parameters and certain cardiac biomarkers (NTproBNP, cTnI) and to evaluate endomyocardial biopsies in dogs consuming various custom diets representative of grain-free and grain-inclusive options in the current market. The hypothesis was straightforward — these diets would not negatively impact the cardiac health of a cohort of purebred and mixed-breed dogs over a seven-month period.
The results were telling: while there was a noticeable treatment effect on the ejection fraction (EF), all EFs remained within the reference interval. Importantly, no treatment effect was observed for other cardiac parameters and biomarkers among the dogs, regardless of their specific diets. The study concluded with no observed development of cardiac dysfunction in the test subjects based on echocardiographic parameters, selected cardiac biomarkers, or endomyocardial biopsies.
This conclusion underscores the need for future research to pivot toward isolating individual cases to pinpoint the precise variables and potential mechanisms at play in instances of suspected diet-associated DCM in dogs. The quest to decode the relationship between canine diet and heart health, it seems, is an ongoing journey. Understanding the science of canine nutrition is paramount in providing our dogs with the healthiest nutrition.
This is another piece of research that debunks the theory that plant rich dog food containing pulses including peas, chickpeas, fava beans and lentils were dangerous for dogs and a potential cause of DCM in dogs.
