When you change your dog's food, it can potentially impact their digestion, as their system needs time to adjust to the new ingredients and nutrients. To minimize any digestive upsets, it's best to introduce the new food gradually. Mix increasing amounts of the new food with the old food over a period of 7-10 days. This allows your dog's digestive system to become accustomed to the new food, and it can help prevent diarrhea or vomiting.