Q. Is my puppy the runt, we went to see him and he is the second smallest, but he was eating fine, other puppy were jumping on him and he was alone.
A. If a bitch is bred every day (not advised) or every other day for several days, the puppies from the last breeding will not have been in utero as long as the ones from the first breeding, and so will have had fewer days in which to grow and will be smaller than their "older" littermates. This could be why your puppy is smaller than some of the others. He simply may not have an assertive temperament, but rather a submissive one, so the tough guys jump on him. I would ask the breeder about his general behavior, as you may have just caught him on an odd day. I am available for consult if you have more questions--just click on the link on my profile page.