In the never ending search for food Hank can tolerate I picked up a small bag of Merrick grain free on a whim. The fish one. His poops have been normal now for a week. Still some farts and belches but no big piles of yellow mushy poops. Has anyone fed this long term? Any thoughts? The vet was wanting to do either Royal Canin or Science Diet Rx food next with him. He has had horrible digestion on all other grain frees.