I found an abandoned pup in a box. He was with other pups but he's the only one that was alive. People must have thrown them away, he didn't want to drink formula milk, so I gave him dairy milk as it was already late in the evening and the stores were closed. But I bought soy milk and he drinks it, and so far it doesn't seem like he's getting sick. But I'm worried he's not getting the vitamens and minerals he needs. Can someone help me?