I have been rotating Fromm 4 Star Grain Free with Sophie for over a year with no issues. The only one I won't use is the the Chicken. I've used Salmon Tunalini, Pork and Pea, Game Bird, Lamb and Lentil, Beef Frittata, Duck and Sweet Potato, and Salmon al la Veg (not grainfree) and cold switched at the end of each bag with no problems. Love this food!