Last July, the FDA’s Center for Veterinary Medicine announced that it had begun investigating a “potential link” between “certain pet food ingredients” (peas, lentils, potatoes, and other non-grain sources of starch often found in “grain-free” pet foods) and the rare but deadly canine heart disease dilated cardiomyopathy (DCM).

The FDA’s investigation was prompted by a group of American veterinary specialists from major research universities, including the University of California at…