Rotties are very smart and protective. My daughter had one that someone dumped out in the country near her house. Rottie was the 4th dog in her family and it made sure that all humans and dogs were safe from everything every day.
I had a chiropractor who kept his Rottie in the office with him. When we patients were on the tables, Dog would walk around and make sure we were all ok.
I guess it was uncomfortable for some people, but I liked having him come in and check on me.