The FDA conducted a four-year investigation into a potential link between grain-free dog food diets high in peas, lentils, and potatoes and the development of dilated cardiomyopathy (DCM) heart condition in dogs. The agency received over 1,300 reports of DCM in dogs, prompting the investigation. However, in December 2022, the FDA quietly announced that it couldn't establish a causal relationship between the diets and DCM, leaving many questions about the handling of the investigation unanswered.

The investigation led to upheaval in the pet food industry, with sales of grain-free dog food plummeting after the FDA named 16 brands associated with DCM reports. Financial conflicts of interest among veterinary cardiologists involved in the investigation raised concerns, and ongoing research continues to explore the potential connection between high-pulse diets and cardiac issues in dogs. Despite the FDA's inconclusive findings, caution is advised regarding diets high in peas, lentils, or potatoes for dog owners, while the overall impact on the industry and affected pet owners remains unresolved.