One of my neighbor's used to raise Rottweilers. He walked them around the neighborhood without a leash. I had a BC and 2 Corgis at the time. I started carrying a cattle prod. Then all the Rotts were on a leash.
People with big dangerous dogs are often the last ones to use a leash. They need to wise up. I found the cattle prod to be the great equalizer.
My Dad had wild dog problems working in Puerto Rico. He used a lead horse whip that he carried in his back pocket. I had a paper route as a kid with some loose big dogs. I carried the whip in my back pocket. It gave me some confidence and I never had to use it.