I agree it is horrible and I would NEVER do it, and hate to even think of it.. But you can't be so naive to think, that these kind of things don't happen.
Culling is the word. I know farmers from way back that would not think twice about it,any animal, they are not pets or loved ones, like we are, they are food,and income and survival.. Kind of like a Puppy Mill, you don't really believe that a mill would humanely ethanize a pup.. they don't care about them when they are ALIVE, let alone dying or deformed..
Bottom line, as much as we all hate it,and don't want to think about it.. It happens, everyday.
I know we are talking about dog breeders, but I hate it for ANY animal. But it is a reality. As horrible as that is.