Ninety-three percent of the 524 reported cases of a specific heart disease in dogs, dilated cardiomyopathy (DCM), involved dog foods made with peas and/or lentils, while 90% of the afflicted dogs had eaten diets labeled as grain-free. A smaller proportion contained potatoes. The U.S. Food and Drug Administration (FDA) released that information and more in an update to their investigation into canine dilated cardiomyopathy (DCM) cases correlated to certain grain-free dog foods. Between January 1, 2014 and April 30, 2019, the FDA received 524 reports of DCM, some involving multiple pets.
Most frequent ingredients or characteristics of DCM-related dog diets
- Grain-free – 91%
- Peas and/or lentils – 93%
- Peas – 89%
- Lentils – 62%
- Potatoes/ Sweet Potatoes – 42%
No causation found between dog food ingredients and DCM
While the FDA has found these correlations, they have found no causality. Thousands of dogs have eaten the same diets as the dogs stricken with DCM, to no ill effect. FDA lab analysis of grain-free versus conventional dog foods revealed little difference in levels of minerals, amino acids, taurine, protein or other nutrients.
“Another puzzling aspect of the recent spike in DCM cases is that they have occurred just in the last few years,” wrote FDA officials in the update. “The FDA is working with the pet food industry to better understand whether changes in ingredients, ingredient sourcing, processing or formulation may have contributed to the development of DCM."
Pet food trade group reaction
“The Pet Food Institute (PFI) agrees with statements from the U.S. Food & Drug Administration (FDA) that this is a complex issue with many factors requiring scientific evaluation,” PFI President and CEO Dana Brooks said in a press release. “PFI members are collaborating internally and sharing relevant information for scientific analysis as we work together to expand the understanding of any potential connection between DCM and diet.”
FDA determination of grain-free dog foods
FDA agents examined dog food labels to determine whether the product contained corn, soy, wheat, rice, barley or other grains, and whether the products contained peas, other lentils including chickpeas and beans, or potatoes (including sweet potatoes).
Animal protein sources in the reported diets included a wide range of conventional and novel dog food ingredients. The most were chicken lamb and fish. Less frequently encountered dog food proteins sources included kangaroo, bison and duck. No one animal protein source was predominant.
In July 2018, the U. S. Food and Drug Administration alerted pet owners and veterinary professionals about reports of canine dilated cardiomyopathy (DCM) in dog breeds without genetic predispositions to the disease. Although not associated by heredity, the dogs did share a common factor. They frequently ate dog foods containing peas, lentils, other legume seeds, or potatoes as main ingredients.
High levels of legumes or potatoes appear in diets labeled as grain-free, which the FDA pointed out in their warning, but it remains unknown how these ingredients are linked to cases of DCM.