This has been circulating for many weeks on FB but now hitting MSM, FINALLY.
"FDA: Dog heart disease, grain-free dog food may be connected
Food usually contains peas, lentils, potatoes"
[clickondetroit.com]grainfree-dog-food-may-be-connected
Companies use these ingredients to boost protein levels.
Unless you make your own cooked or raw meals it's very hard to avoid.
There is also suggestion in nutrition circles that the ingredients in question block absorption of taurine.