[RileyDC]

Originally Posted by Wylie's Mom

It's so variable...depends on the dog and the dog's reaction to any one ingred. I've always done hard switches with all 3 of my dogs, and have never had a problem. But who knows, maybe there is one food that'd bother one of them. I don't think you can really go wrong either way; you're not going to hurt them by doing a slow switch.