This is my own experience. Before, I was giving Origen and then I switched to Purina Bifensis. And now I mixed this one with the rest and my dog chews it and then spits it out, I understand it from the black color of the kibble. Also, only the first day he ate it, the next day he had a bit of soft stool, maybe it was because of the change, I don't know. It's a shame because it's quite expensive. I will try to trick him into eating it, maybe I will have to buy Purina and mix it. That's it.