I would just switch cold turkey. Some have a little sensitivity, others have absolutely no problems. Neither of my dogs had a problem and my senior collie always had a sensitive tummy. I now feed Prey Model Raw as it's more cost effective - my collie eats alot more than my yorkie! I know that Natures Variety has a spot where you can put in your dogs weight and activity level and it will tell you how much to feed. Good Luck!
