Sure, but it not just dogs. My Dad raised pigeons and bantam chickens. Breeding father to daughter and son to mother is pretty routine...you just kill the undesirable offspring, which is what some cultures have done with undesirable human offspring as well. Ever hear of a "squab knife"? (Used not just for killing the culls, but also because some twisted people actually like to eat squab.(baby pidgeon)) Often the culls were allowed to grow to conventional eating size. Dad would donate them, both pidgeons and chickens, to needy senior citizens in the area. They were quite glad to get them.