It is natural to clench your teeth or even your fists when you learn about such preposterous cases of animal abuse as chopping off the paws of kittens and then leaving them to perish. And justifiably so too. No man in his right mind would contemplate such a thing, not to say to do it, and he deserves to be condemned.
However, while not trying to give the coward any excuse (and there really isn't any), I do wish to make the point that it may be worth asking what sort of childhood experience could have turned the person into what he or she is now. I simply cannot accept the argument that he (might even be a she) is what he is because he is born with such an evil character. I believe that what makes us what we are is a combination of nature and nurture. We do have our inborn character traits, but we are also very much moulded into our present selves by powerful social influences. So just as child abusers invariably have a childhood history of having been abused by their parents, animal abusers also almost certainly have had traumatic experiences that transformed them into the 'monsters' they are now.
I believe that in some extremely depressing cases the pain or torture in the childhood was so severe that it didn't even leave the sufferer with the choice of how he (again it might be a she) would face it or what kind of person he would like to become in the future. Without a glimmer of hope, radically twisting their outlook of life was the only way to save himself from completely falling apart. Such cases are truly tragic.
But I also believe that in other less extreme cases it is still possible for the victims to choose whether to let the abuse go on through them or dare to try to break the spell. That courage to pick up the pieces is what makes the difference between a healed life and a dark life. As Ernest Hemingway said, "The world breaks everyone and afterward many are strong at the broken places."