Hermione….I agree with the probiotics and enzymes. They should help. However, the Blue Buffalo has grains (rice) and most likely has way less protein than the EB Primitive Natural, which is EB’s highest protein variety. I do know that my 3 dogs could not make such a switch easily, but they are older dogs. Anyway, it can be done, but it may take longer for your dog to adjust to the “richness” of the EB Primitive Natural. Have you thought of transitioning to a lesser protein Earthborn food, like Meadow Feast, or first to one of their grain inclusive foods then when the dog is used to that food gradually switching to, say Coastal Catch or Meadow Feast, then finally to Primitive Natural, providing your dog can handle it along the way? It’s been my experience with my dogs that when switching to a new food if the new food has a similar protein/fat and analysis makeup to the old food the switch goes much easier than if the new food is a lot different makeup. Once I’m on the new, similar food for awhile I can then go on and transfer to a higher protein of the same brand. I hope this makes sense lol.
