Common grain-free dog food ingredients may fuel canine heart disease

A new study from Tufts University found that some ingredients in dog food can cause heart disease in our canine companions, and the same ingredients are often found in grain-free dog food products. The study specifically addresses dilated cardiomyopathy (DCM) in dogs, a disease that affects the heart muscle.

To investigate the possible link between diet and DCM in dogs, researchers examined both traditional dog foods and the foods associated with canine DCM by the FDA. More than 800 compounds were evaluated, with the study finding that 88 biochemical compounds in dog food products that the FDA has linked to DCM were higher.

The study also found 23 compounds that are found in lower amounts in these DCM-linked dog foods. Additional work narrowed things down to the “top 30 connections” that separate the two different dog food groups (DCM-connected and non-DCM-connected). Finally, the researchers say that four specific ingredients differentiate these two groups: chicken / turkey, rice, lentils, and peas.

Peas in particular were most associated with higher concentrations of the potentially problematic compounds in DCM-bound dog food. Dog foods related to DCM are mostly marketed as “grain-free” options, according to the study, using ingredients like sweet potatoes and potatoes in place of more common ingredients like corn and rice.

The study further explains:

When all four distinguishing ingredients are plotted, the ingredient-compound relationship for peas shows tighter bars for peas when compared to the other ingredients, supporting the possibility that peas may contribute to higher concentrations of these biochemical compounds. Unlike peas, rice and chicken / turkey are primarily associated with open bars, indicating lower amounts of the compounds associated with these ingredients. Compared to peas, there are fewer ingredient-compound connections in lentils, but in a similar direction to peas.

The researchers note that they cannot currently say whether the presence of peas and “to a lesser extent” lentils and the compounds they contain are the cause of DCM in dogs. However, they note that dog foods containing these ingredients have also been linked to the compounds found in higher concentrations in DCM-linked diets compared to others.

“The results support peas as the leading potential ingredient in nutritional DCM in dogs,” the study concludes. However, that does not mean that these ingredients pose an inherent risk to dog health.