It sounds extreme to me. How old is this dog? How much socialization did he have as a very young pup? How many "strangers" visited? It sounds like not enough. He should not go balistic when you're there. My Dobe is safe with strangers if he's outside in the yard....just watches, maybe gives a few woofs while the person is driving up the driveway. But when they get out of their car, he just waits and watches. He'll bark, when inside, but the minute I tell him "enough" and I am walking toward the door, he sits and watches. That's it.
He has prevented someone from coming in the house when I was not there to open the door. I was home, but in the shower. He growled a throaty growl to warn the person not to come in the house, but didn't go balistic, just sat there in front of the door, grrrrr. (this person told me this when I came out on the porch) Then Lyric was friendly.
He did go balistic once when a stranger walked into my son's apartment when we were staying there. The stranger really was a friend, but he walked in in the middle of the night. Door was left unlocked. Weird guy.....just had to talk to my son. Lyric knew that was weird too. He didn't lunge or bite, but barked/growled viciously after we both leaped off the couch in utter surprise.
So, in other words, he knows when someone has business here and when they don't. Just today I had guys installing Direct TV. All the dogs yapped a little when they knocked on the door. Once inside, after some sniffing and greeting, they just settled down. Lyric curled up on the couch with one eye open. LOL. He's more of a silent observer than one to make a lot of noise. He's really good at distinguishing between normal, friendly strangers and someone up to no good. I've had numerous people knock on my door that he doesn't know when he's outside and I'm not, and he just watches...He looks a little suspicious, but waits for me and then you can see his eyes watching me, then the person, then me. It's interesting.
One time when I was not home, my niece came in with a guy who Lyric didn't know. Lyric loves my niece. So, it wasn't on account of her, but the guy....Lyric growled and was quite toothy/vicious looking and all muscled up. She told her friend to get out of the house, NOW. (She was here to take care of my dogs when I was gone all day for a long time.) So, I take it, that Lyric didn't know whether my niece had things under control or not....if he was protecting her. He didn't seem to get the idea that this guy was OK to be in the house when I wasn't home and that he belonged with my niece, that they were together....or something. He was in his crate, as he was still too young to be left loose in the house... and she went back in my bedroom to let him out and this guy was standing in the kitchen as Lyric ran into the kitchen. He was very taken off guard. So, here's this strange man standing in the kitchen, my niece coming back from the bedroom and Lyric just was positive that this was not normal. The guy said, "Oh, it's OK. He'll be fine." Meanwhile, Lyric is really quite vicious, but no going after him...just standing in one place. My niece said, "NO!!!! Get out NOW. Go wait in the car." I felt awful afterward when she told me all this.
Sorry for all my rambling stories...thought they'd give you an idea how different dogs behave differently in certain situations.
So, socialization...lots of it is so important and before about 3-4 months old and continuing. You may need some professional help. This sounds potentially dangerous. I hope things will be OK. Good luck.
