I'm an avid coonhunter and I used to feed nothing but Purina. But the dogs stool always looked "loose". Looked as if the feed was going right thru them. Had them all checked for worms. None were wormy. Vet suggested I switched feed. So I started doing some checking. I ended up switching to Ultra dogfood. Its made here in Indiana. There is ALOT less kennel mess and the stool is dark and firm. Which the vet told me that would be a sign of them getting all the nutrients out of the feed. They look good, their coats look good. And I dont have to feed quite as much like I did with the Purina. By the way, I fed high pro to my older dogs and puppy chow to the pups.....This wasnt something that happened all the time with Purina. It started happening about 5 months ago. I dont know what they changed in their formula, but for all my dogs to react like they did, something had to change. So I did as well.......to Ultra.