My wife had our maltese on purina pro plan for about two years. When I brought home Ace the breeder fed Canidae and so I did as well but Ace liked the purina pro plan and would steal it from the maltese bowl. So I was feeding about half and half. The maltese always had tear staining and they are notorious for it and Ace began to get staining too. I tried several things to rid the staining but what worked was the change in food. We quit feeding either dog the purina and now feed Whole Earth Farms and Fromm. No more tear staining in either dog. Regardless of that just comparing the ingredients between purina pro plan and Whole Earth Farms and Fromm and its unmistakable to me that they are superior foods to the purina. The reason I feed both WEF's and Fromm is that on just the Fromm Ace was having a little more difficulty pooping, when I introduced the WEF's in the mix, the bowel movements improved alot. Actually of the two, Whole Earth Farms and Fromms I prefer the whole earth farms. Larger kibble size for one and better bowl movements. So now I'm basically feeding Whole Earth Farms adult.