Not quite on topic, but if you ever experience problems with your dog's digestion just after opening a new bag of dry food, be suspicious. It is definitely possible to get a "bad" bag of food. If you have multiple dogs, this problem is easier to be aware of. A friend got blindsided when a new shipment of feed for her goats pretty much wiped out the whole herd because of a mistake in formulation. This can happen with dog food too!! It is one of the first questions an astute vet will ask with an unexplained digestive upset.
R