Just to support EastJenn further....I do not recommend feeding raw and kibble in the same meal. If you want to introduce raw foods slowly and still feed kibble, then I advise feeding it in separate meals. Feed a small amount of raw in the morning, where you have all day to see how they process and stool is affected - feed kibble at night.
Long term, the goal should be to ideally feed one or the other however. You are not providing great benefit by feeding both long term - just taxing the digestive system more with all of the different forms etc. to break down and process. For optimal digestive efficiency, you want to get dogs eating 100% raw or homemade cooked - otherwise, I would just stick with kibble.