Where did you get this puppy from that the breeder is letting him go to his new home at such a young age? I would also be contacting the breeder to tell them about the vet's finding and see what they have to say about it.
"To close your eyes will not ease another's pain." ~ Chinese Proverb
“We must not refuse to see with our eyes what they must endure with their bodies.” ~ Gretchen Wyler