Doesn't Like Guests

Hello! We've had my dog, Murphy, for 7 years. He was a rescue from New Rattitude. Ever since we got him, he doesn't trust any guests. I got him to bond with my grandma, aunt, and best friend, but he acts violent whenever someone else comes through the door. We have had to put him behind a gate in the room he sleeps in whenever people come over since we got him. Do you think there's any way we could train him to accept other people?
If it helps, he's completely fine when he's out of the house. He'll act uncomfortable if someone gets too close to me on walks, but otherwise only is aggressive at home. Could it be territorial?

People will want to say something positive, but there is very little that you can do to curb this at 7 years old.

That's fine. I just wanted to know if there was anything I could do. He's actually 9 years old, we got him when he was 2. We think he could have possibly been abused in a past home because he was found in bad shape, so it might be something that mentally scarred him in the past that causes him to be overprotective. Thanks for your feedback anyways.

The only thing you can do at his age is accept him for what he is. Does he ever complain that you are not perfect? Nope, so go find his toy and play with him then go snuggle............ As long as he loves you for what you are, and that you know he cares about the time you spend with him who cares about anyone else. He was probably given up for what you are describing, I has a rescue like this once, I was told that she ate a woman's leather couch because she was not let on the furniture. I had to give her permission to hop on my bed with me the first couple weeks with me. Once there she put her head on my pillow near my neck and stayed there happily for 13 years and she never ate my couch or bed.

I do love him for who he is. I just thought being behind that gate barking whenever guests come over could be stressful for him. Whatever I do is in my dog's favor. He's like a sibling. I'm only 14, so he's been with me for half of my life. I hope I didn't give the wrong impression earlier.

Your dog is between 50 and 60 years old when compared to a human, he is not going to change now. So you have to adapt to the situation that you have, not adapt the dog, he is just too old to change very much at this point.

My last dog didn't like visitors and could be snappy when they arrived. I found the best way was to put her in a different room before I opened the door to admit them. Once everyone was settled, she could then be let out and left to either accept or ignore them.

We already have adapted to the situation. He's been like this for seven years. I just wanted to know if there was a way to make the whole situation a lot less stressful for him.

Sadly, my doggo is a bit too violent for this. He'll bite them as soon as he gets the chance. It's not just growling and barking. We're afraid that, if we let him loose, he'll bite the person and have to be put down. We usually adjust him to people (we don't trust just anybody) by putting him on a leash for the first few visits.

So your dog has been attacking people for 9 years and now you ask for help? Again what breed is the dog, it matters