I've heard of dogs on raw who were given unrestricted access to kibble and bloated, but I wouldn't say that was "caused" by the grain.
There's also some evidence that partially moistened kibble increases risk and that wet food is less risky than dry food.
But I haven't seen any hard evidence at all that says that grains themselves are a contributing factor.
There's also some evidence that partially moistened kibble increases risk and that wet food is less risky than dry food.
But I haven't seen any hard evidence at all that says that grains themselves are a contributing factor.