we have feed our last 2 labs Iams and limit their table food, always had good coats, and no real issues that could be food related. the new pup came eating something else I think Pro Plan, so when she gets to year we will try and get her on Iams too, I think the most important thing is to keep it regular and not mix it up too much, have had to do a couple of GI resets and they are not fun