What do i feed a malnourished puppy?

Yesterday I was at a family reunion with my boyfriend and 2 people came up with 3 adorable weimeraner puppies (about 7-9 weeks). Once everyone was cooing over the puppies the people slipped away drove off. All 3 puppies had distended bellies and diarrhea. We are taking him to get his shots in the morning but I want to get him started on a regular feeding schedule...any ideas about what kind of puppy food formula would be best for him? Also we are trying to kennel train him but he is very winy and cries when i put him in there during the day time. any suggestions on how to get him from barking/wining so much?