Myths and Facts about DCM in Dogs

In this article:

• What is DCM?
• Does grain-free dog food cause DCM?
• Does dog food with legumes cause DCM?
• Is DCM a new problem?

Dog owners only want the best for their dogs. And when it comes to diseases like dilated cardiomyopathy (DCM), a potentially fatal heart condition, it can be hard to distinguish truth from fiction. 

Here’s a guide to myths and facts about DCM, and how current veterinary research can inform your choices to give your dog the best chance at a long, healthy life.

What is DCM?

DCM is a degenerative and potentially fatal disease of the heart muscle. In dogs with the condition, a weakened heart muscle leads to stretching (dilating) of the heart chambers and reduces the heart’s ability to pump blood. Over time, the cycle of an ineffective pump, over-filled chambers, and progressive stretching of the heart walls can lead to congestive heart failure—a buildup of fluids in the chest and abdomen. DCM can afflict dogs, cats, and humans.

Signs of DCM in dogs can include rapid or labored breathing at rest, coughing or gagging, pale gums, weakness, lethargy, and collapse or fainting. However, some dogs show no sign of illness at early stages, and some may die suddenly due to acute heart failure or an arrhythmia (irregular heart rhythm).

Veterinary researchers are still learning about the underlying mechanisms that drive the development of DCM in dogs, but research shows that some breeds are predisposed to the genetic form of the condition. It more frequently afflicts large and giant breeds, and is very rarely diagnosed in small dogs. High-risk breeds include Doberman pinschers, Great Danes, boxers, and cocker spaniels. 

Myth: Grain-free foods cause DCM.

Fact: Research has found no causal link between any grain-free diet and DCM.

The myth that grain-free foods cause DCM spread with the publication of a June 2019 report from the Food and Drug Administration. 

Between January 1, 2014 and April 30, 2019, the FDA collected reports on 560 dogs afflicted with DCM, of which 119 died. These reports led them to investigate a potential link between diet and this disease. Their 2019 publication announced a “potential association” between diet and DCM in dogs. 

However, the FDA investigation failed to find a link between grain-free diets and DCM. The FDA emphasized that it hasn’t “declared any specific pet food products unsafe or definitively linked to DCM.” In December 2022, the FDA announced that it wouldn’t release further updates to their investigation “until there is meaningful new scientific information to share.”

Further, the small number of cases collected for the FDA investigation was not  representative of the US pet dog population and their diets. In a 2020 paper published in the Journal of Animal Science, the authors wrote in the abstract that the veterinary community ought to be asked to provide information for all cases of DCM in dogs, regardless of diet. And in July 2022, the accountability organization 100Reporters published an article that found some vets were instructed to submit only DCM cases implicating grain-free pet foods.

A University of Missouri paper from 2022—also published in Frontiers in Animal Science—noted that, although there had been a small increase in the number of DCM cases  suspected to be associated with diet, there was not a corresponding increase in the overall number of DCM cases nationally—this despite a fivefold increase in sales of grain-free pet food between 2011 and 2019. Almost all major dog-food companies in the US now sell grain-free options.

In July 2025, the Journal of Animal Science published a Hill’s Pet Nutrition study. The paper’s authors wrote that an 18-month feeding study showed no adverse cardiac effects in dogs fed a grain-free diet as opposed to a grain-inclusive diet.

Myth: Legume-rich foods cause DCM.

Fact: Recent feeding studies show no link between legumes and DCM.

In September 2020, Kansas State University hosted a virtual scientific forum for academic, industry, and veterinary medicine experts to share research on potential causes of non-hereditary DCM in dogs. One presentation explored the history of pulses—the edible dried seeds of legumes—and their use in pet food. Pet foods have incorporated pulses since the 1980s. As the FDA later noted, “it is important to note that legumes and pulses have been used in pet foods for many years, with no evidence to indicate they are inherently dangerous.”

The same 2025 Hill’s study referenced above included a group consuming pulses, and found no adverse effect on cardiac function in dogs eating them.

In 2023, the University of Missouri published a paper in the journal Frontiers in Animal Science. Over seven months, researchers fed 65 dogs four test diets: two grain-free diets with pulses and potatoes, and two grain-inclusive diets without pulses and potatoes. None of the dogs developed DCM, and the authors wrote that the study “was unable to identify any dietary correlation to DCM.”

It’s also worth noting that, according to the American Veterinary Medical Association, there are about 87.3 million pet dogs in the US as of 2025. The FDA acknowledged that “most dogs in the US have been eating pet food without apparently developing DCM.”  It is difficult not only to know the true number of dogs suffering from DCM, but what factors may ultimately cause this condition in these dogs, including their diet.

Myth: Nutritional DCM is a new problem

Fact: Nutritional DCM has been a problem for decades, at least—and research is ongoing

While reports of canine DCM between January 2014 and November 2022 made headlines, the disease is by no means a recent problem, or one that arose after the increased popularity of dog food without grains.

A paper published in 2003 in the Journal of the American Veterinary Medical Association analyzed 12 cases of canine DCM between 1997 and 2001. The dogs included in this retrospective study all ate a commercial dry diet containing lamb meal, rice, or both as primary ingredients.

A crucial result from this paper was that consumption of certain commercial diets may be associated with low blood or plasma concentrations of a compound called taurine. Taurine is an amino acid, which are the body’s building blocks for protein, that is highly concentrated in certain tissues, including in the heart. Natural sources of taurine include fish and shellfish, meat (both muscle and organs), dairy, and eggs. Critically, taurine isn’t found in plants, including legumes and grains.

This paper also reveals that the presence of grains—in this case, rice—isn’t necessarily a factor in developing or preventing DCM. And meat meals aren’t made with the sort of muscle or organ meat that’s packed with taurine.

While nutritional DCM does occur, it is a rare diagnosis and is likely multifactorial—influenced by genetics, individual animal metabolism, diet, and more.

We’ll all benefit from more evidence-based research on DCM, and from an ongoing commitment to distinguishing myth from fact when it comes to our dogs’ wellbeing. We will continue to provide updates as new information becomes available. 

The Farmer’s Dog food is always formulated by on-staff, board-certified nutritionists. We’ve also conducted AAFCO feeding trials on multiple recipes and partnered with the Cornell University School of Veterinary Medicine on a long-term feeding study.

If you have any questions about what diet is right for your dog, talk to your veterinarian—they’re the person who’s most qualified to make a recommendation that accounts for your best friend’s particular needs and medical history.