my friend bought a pup 7 months old to use as a stud dog.forward fast to just over a year old.he had his semen tested to see if he had live sperm and he did.he mated with a proven bitch and a maiden neither got pregnant.he was then put to another maiden she never caught either.then put to two more proven bitches but neither of them caught.where would one go from here? just get him castrated and kept as a pet.she is a hobby breeder.

If his sperm was viable he'd surely have managed to get at least one of all these bitches in whelp?   It would be really hard luck otherwise.   I'd get his sperm checked again, perhaps by a different vet? and see what it shows - could be low even if some are there.    Otherwise I'd take it that it just isn't meant to be and either keep him as a pet, or sell him as a pet.

Castrate him?   No.   If he's not fertile, why bother!!!

Get him to a repro vet, ge may have good sperm but sperm count and how quickly they move is what needs to be considered. I wouldn't just get him castrated, ge can still be shown or worked and remain entire.
I wouldnt get a regular vet to do this check. There are many repro vets about and they can do this for your friend.

thank you for your constructive answers i will tell my friend.