No one would ever mess with Joe, a 2-year-old American Bulldog. Not just because he is 90 pounds of intimidating muscle, or because he roars instead of barks. He lives in a walk-up third floor apartment in a marginal neighborhood, and you can hear his heavy tread above you as you enter the foyer of the building. No, to me, none of those factors is particularly off-putting. I’ve worked with larger dogs, in worse communities. To me, the most daunting aspect of Joe is that the d