Grapesoda

must be... scent hounds are not supposed to be too sharp however they can judge a persons mood 300 ft away... found this online:

Old English Mastiffs are known to be affectionate, loving, gentle, and calm. Even Mastiff owners think their beloved Mastiffs are more like a toy breed in character and never would regard them as guard dogs.

Often times, Mastiff owners have never seen their Mastiffs as protectors. They are one of the most intelligent dog breeds and often times are friendly to unfamiliar guests when their master is around. However, Old English Mastiffs are great guard dogs and they are not arrogant of their massive size but are confident that they can take on any enemy or intruder who might threaten their master, family, or property. When an Old English Mastiff sees an unknown stranger come near their master or territories and senses conflict, he will instantly place himself between his master and territories and the stranger. Believe me, as the owner of two Old English Mastiffs, I thought they were the dumbest, clumsiest dogs in the world. Actually, my male Old English Mastiff has the nick name of Dumb Dumb which he inherited when he was about 9 weeks old because he chewed on rocks. Real rocks from Planet Earth. I thought then that Old English Mastiffs were just dumb, clumsy, massive good looking dogs. However, when the water meter maid came over to shut off my water because I was just a few months late on my water bill, Dumb Dumb wanted to attack the man who wanted to deprive our family of water. I then realized that Dumb Dumb was not so dumb after all and a great watch dog.

Mastiffs might be clumsy, sloppy, and look seem like a Baby Huey, but they do make excellent natural protectors. The Old English Mastiff is one breed that does not need protection training. From my personal experience, Old English Mastiffs get their protection instinct after the age of two years old