Laura:
You better take him to a vet to be sure he does not have a blockage. Dogs throwing up can also be a sign of Pancreas issues and the constant diarrhea could be an issue with bad bacteria over growth in his small intestine that takes a specific antibiotic to clear up. Doubt if the dog food is causing this problem. One the other hand if you want to switch dog foods I would pick one that only had 1 animal protein, such as Taste Of The Wild, lamb or Taste Of The Wild Pacific Stream. All other Taste Of The Wild products have mixtures of different animal proteins.
