Have to weigh in here...
I've posted about Bailey's attack mode once before, but she hasn't forgotten and continues her hatred of that person. We have a neighbour, who has moved in with the mother of his child, and awhile ago there was a party in our condo complex which both my husband and he attended. When my husband came home he brought two friends for a nightcap. I was in bed with Bailey, but she went into overdrive, and barred the way into the living room from the hallway. She wouldn't let my husband in or the one neighbour she was very friendly with, she block the path, hunched down, hair up, snarling and barking, and her bark was ALL BUSINESS. Up until then, I'd never seen anything like this from her. She wasn't blocking her Dad and she wasn't blocking Danny, and she hadn't lost her mind, it was something different...it was the other man.
And this hatred continues even now months later. That man can't walk past our house without Bailey giving him the business. And yesterday, he was putting garbage out for pick up and passed us while we were sitting outside with our two dogs. Kaleb was called back easily, but Bailey got within inches and was full on threatening him. I finally got her under control and back beside me, but she lunged again when he walked back. I sought to assure him that Bailey is gentle, good-natured dog, but....wow, she thinks he's a really, really, bad man. I TRUST HER JUDGMENT. And my husband has been told that that man isn't allowed in our house. I don't know what is wrong with him, but Bailey and God know and he's in their bad books.
Trust Your Dog...they can smell the bad intent on people.