If i needed a security dog i would go with a Rottweiler. The one i had was very devoted to my wife and i. When the visiting nurse was comeing to check on my wife the rott would plaster her self against my wife and watch every move the nurse made. That dog went everywhere with me. Only seen her show any aggression twice in the years i had her. Woke up at 2:30 one morning to a light shineing in my bedroom window. There was a car parked on the end of my driveway shineing a spot light on the house and pole barn. Had a very long driveway. Put the rott in the truck and drove down there. One of the guys get out of the car and starts toward my truck. Rolled my window down and told him he better move on. He said [bleep] you [bleep]. Get out of the truck and i will kick the crap out of you. Darker than hell. Don't think he seen the dog. Got out of my truck and she got out with me. She was all teeth when she got out. Not sure why but they decided to leave. The second time she was in the back yard with me. She headed for the house. I went to the house to see where she went. Wasn't normal for her to take off like that. Got up there and she was going crazy tryin to get in a car parked there. Had a hell of a time trying to get her off the car and in the garage. Finally did and ask the guy what he wanted. He wanted to know if he could hunt behind my house. Told him sure but the dog is usually out. He said he thought he would look for another place to hunt. Sorry i got so long winded. I sure do miss that dog. She laid by my chair one evening got up and pucked and fell over dead.