We generally recommend transitioning food over the course of one week, gradually phasing out the old food and introducing the new. For the first two days offer a meal that is 25% new food and 75% old food. After that, move to 50% and 50% for two days, then 75% new food and 25% old food for two more days. After that your dog should be ready to eat only their new food!During this transition you will monitor for any vomiting, diarrhea, or appetite change that would indicate your dog is having trouble with the new food. For more on transitioning dog foods see our guide here.