Now! I know some people will wait until weeks after all their shots are completed but I believe socializing should be done asap! Obviously, NO dog parks, or Petsmart, or places where they can get diseases but find dogs you know are healthy (friends dogs, etc) at least. I do believe Jackson is a better dog because of it. He was exposed to many different dogs & people at an early age (healthy dogs, my parents, my friends, etc) and he seriously has never met a dog he doesn't like. I don't know, I just personally believe the earlier the better
and my vet was fine with him going out in our backyard after his 2nd set of shots was completed. I think exposing them to the world is very important early on.