I've started mixing some Orijen Puppy large breed formula into Rocky's Innova puppy and it is causing him some MAJOR gas problems. He's only getting about a quarter cup mixed in with a full cup of Innova and some Innova canned, but it's enough to cause bad gas and some mushy diarhea and now he doesn't even eat his full meals. He's leaving behind the last half cup of food in his pan and normally he devours his food. I haven't added any pumpkin or anything since it's so little Orijen and the whole point was to start mixing in a grain free food. Has anyone else had this much trouble switching over to Orijen?