An interesting assertion - I'm not sure I agree. While Vick presumably had no empathy for the dogs he more or less killed for sport, I don't think that means he's incapable of empathy for a dog.I also have no problem killing animals, even dogs for food. What I do have a problem with is torturing them to death for entertainment. I am also completely convinced that anyone engaged in said torture cannot be rehabilitated.
That's just my intuition - never studied empathy, but it seems like an interesting topic.