I've had my cats on Purina Cat Chow from day one and have never switched except to Purina Indoor Formula and that's when Creamsicle's itching and scabbing started. Someone on PT told me that the indoor formula has more dyes in it and that could possibly be the cause of her allergies. So I decided that I wasn't going to switch or play w/their food any more. If they like it, eat it and keep it down, why switch? They do get wet food occasionally but their staple has been Purina Cat Chow.