So the Bull mastiff is smaller and more aggressive. Our neighbors formerly had 2 old dogs that weighed close to 200 pounds each and they made me nervous just because they were so huge. They have 2 young ones now and I am careful to give them treats through the fence so they will like me. :D
It is sometimes a pain to haul around those 200 lbs, or even a 140 lb Bull Mastiff. That is why I say “active” when I say that no dog breed has ever impressed me like a fit “active” Bull Mastiff.
An inactive Mastiff or Bull Mastiff isn't that great of a dog. They do one hell of a job guarding their bed and the fire - and not much else. You if you are by their bed or the fire - but not if you are out and about.
My brother had to force his lazy Bull Mastiff to “do the rounds” on the property he was caretaker of. She would have rather stayed home, the darn lazy critter! Lucky for my brother HE WASN'T HAVING IT!
One night he heard a bunch of deer that had jumped the fence startle and hit the fence, then reverse and come towards him. The does went to either side, but the buck lowered his antlers and charged straight ahead.
“Freya” the Bull Mastiff sprung into action and hit the buck with her chest, knocking his antlers into the chain link fence and breaking its neck.
That dog ate venison - prime cut - for a month.