I started last week and have been mixing them. We are moving from Nutro to ProPlan. They love the new lamb and rice, so we will see how they do. Boo's stools have been real pellet like but on the new food it is 100% normal. It took me a while to decide to do this but after reading one of Laura's last posts about her dogs and Proplan, I decided it's time to try it.
Good luck with the food change. My dogs are on ProPlan too and are doing well on it.
Blackie and Ranger ...............................Reggie: 1996-2010 "Fly Reggie Fly"
Good luck! I hope they do well on the new food!!