I got a coupon in the mail yesterday for Science Diet-Nature's Best natural food. I thought I would try a little and see how Coco liked it. I can't say she liked it because the kibble size is a lot larger for her tiny mouth. Their claim is that the first ingredient should not be a protein, and that other foods are using too much protein and leads to renal failure. Coco is on the puppy Royal Canin and seemed to be doing ok. The pieces are so small that sometimes I thinks she inhales them and then starts hacking. Does anyone else have any feedback on the Science Diet claims or use that particular food?