Maybe you can just keep trying other better quality food until you find one that works. When Rio was a puppy I wanted only the best for her. Started her off on Innova puppy, switched to Orijen, turned out both were way to high in protein and fat for her. Switched her to Canidae which was lower in fat and protein which she ate enthusiastically at first. She got bored with it, so I mixed in some Now! grain free which she loved. Then I added Bullet to the family and had to find something they both love. Right now they are on Buffalo Buffalo Basics turkey and potato and they love it. I still mix in a little Canidae and Now! for some variety...
I've had to find the balance between high quality and what my furbabies will enjoy, along with what their sensitive tummies will tolerate. I've seemed to find the right concoction... for now.
