I certainly dont see a need to cull an animal that lives, eats, poops and sheds like the rest of my animals, however I do wonder when these deformities start to hurt the animal, and when it is no longer humane to keep them alive. How could I tell that the animal was in pain?

That's my whole view on it, luckily I have never had to deal with the task of deciding what is best for a deformed or sick animal that can't express it's unease.