The only dog we've owner who ever bit anyone  was a rescue Dalmation, a guard breed cursed by Disney's movies.  'How cute" while the dog has hair and tail raised, growling, at the door with me not present.  Tried to walk through him, and was fortunately only nipped.  Idiots!  Can't read the dog, only 'cute Dalmation'!!!
NOBODY tried to walk through Trina, our brown Chessie, who would shake the door, lunging at it while barking and growling, again, in my absence.  When I invited people in, she was very friendly.  Training!
Mary