I still think Dog is Sabretooth, Dog and Sabretooth were beaten by their father. Maybe Dog still had the scars on his face because his powers didn't kick in yet. Probably would also explain the huge hatred he has for Wolverine. Logan looked exactly like his dad, and he also killed his dad. BTW, I've read the comics, and I remember the side by side test Beast did on both to prove they have no relation. But you never know.
