Up until the last few years, I mostly lived out in the country, and I have always had large dogs, too. When you live outside of town where there are coyotes and other predators around, it is always a good thing to have at least one large dog around, and we usually had several.
Great Danes were one of my favorites, but I have also had Boxers and Rotties, as well as Bruno, my beloved Gladiator Doberman.
The big dogs were always well-behaved, and gentle with anyone who came to our house. They loved following along when we went for horseback rides.
We had a huge Great Dane named Mr. Spock (pointed ears), and he and our pastor were great friends because we kept Pastor Reed's mule at our place and he was out there a lot to work with Jerry, the mule.
One weekend, we had to be gone and Pastor Reed was watching the house and animals for us. When we got home, we were amazed to find the front door standing wide open. Apparently, one of us had not pulled it tghtly shut, and Spock had gone inside to guard the house, and he would not let our pastor come up on the porch to close the door.
So, even though Spock knew and loved our pastor; when we were gone, he took his guard dog duty seriously.