Big dogs can be very sweet to everyone and other dogs and the good news is, they will also instinctively protect their owners. The bad news is, they will instinctively protect their owners. My buddy who's a banker bought a Rottweiler for his wife to protect her while he was gone or while she was out walking the neighborhood. One evening he decided to go with her when she walked the dog and he was holding the leash. A little kid strangely ran up to the dog and started yelling and waving his arms like he was trying to scare the dog. My friend said it took every bit of his strength to hold that dog back and keep it from mauling the kid. He said if that would have happened any other time there is no WAY his 110lb wife could have held that dog back and prevented him from tearing that kid apart. They didn't have the dog much longer and got a Chihuahua.
A good buddy got a Schutzen trained Rottweiler for around his house. He had to leave for a couple weeks at a time and he wanted both his wife and house protected.
What a dog, I have been around big dogs all my life and that includes other Rottweilers and that dog was something else.
Alone in the house normal conditions all was OK. In the house in "protection mode" it would be a good idea not to try to get in!
Take him out and he was very friendly to other dogs and people. I could play rough with him no problem. I could spar or horseplay with his master he just watched.
He would only eat from his owners, there could be a piece of meat on the table and it was safe. When my buddy or his wife said some things to him in German the dogs whole attitude changed, you talk about a split personality!
A couple of the neighborhood busy bodies made a complaint about the dog and the cops came up to check things out. One LEO was the Dog Cop.
Bill ran the dog through some drills and the cops were very impressed with the dog. Told the neighbors of what they observed. After a while the neighbors got to know and accept their new neighbor. The one even said unless under orders he was a big baby.