DescentBB

Dog For Sale:
Free to good home. Excellent guard dog. Owner cannot afford to feed him any more, as there are no more thieves, murderers, or molesters left in the neighbourhood for him to eat. Most of them knew him as 'Holy Crap'.

Broadness of the body leads me to think it is a Bull mastiff and not a Mastiff

That looks alot like a bull mastiff. My uncle had one when I was a very small kid. Everyone freaked out because I used to stick my whole arm in his mouth, but he was just being gentle and was playing with me. Id ride him like a horse and id try to pull his bone from out of his mouth. Everyone freaked at that too because he growled at everyone but me anytime he was with his bone, and he'd just play along when I ripped it from out of his mouth. Despite them being so damn big and thus a bit intimidating, they are very sweet and intelligent.

^agreed.