I had a male boxer that was very tolerant of small children but would attack any dog he saw that was his size or larger. That made for some embarrassing walks when I had to restrain him as other dogs went by. Also, boxers are prone to skin and eye disease along with the inevitable arthritis. My guy had papers and came from a breeder, but didn't make it to his tenth birthday. That said, they are great dogs, you just have to show them who is in charge.