[theBCnut]

Yes, his GI tract is used to Purina, especially if that is what the mother was fed. Do a gradual transition, but watch his poop. Orijen is a much, much richer food. If it stays firm you can switch a little faster, if it gets soft slow down. Don’t forget that you can add a teaspoon of canned pure pumpkin to each meal to help with stool issues during transition. Those digestive enzymes and probiotics helps a lot too.