This is my second rodeo with a Boxer so I decided to go grain free since my last boy had a lot of skin issues. He is currently on Wellness Core Grain Free Puppy Dry food since he was 12 weeks old. He has always had loose stools and excessive flatulence. I thought grain free was the way to go. The vet is wanting me to go the Royal Canine route but it seems to be chocked full of grain products and it is THE brand endorsed by this vet clinic. She indicated some dogs are unable to process "richer" dog foods. He is also on the thin side. He does not receive any table scraps or people food. Any suggestions would be greatly appreciated.