Thirty years after it first attained notoriety as an accessory to the inner-city drug trade, the pit bull has become commonplace in the United States. No one knows exactly how many there are, especial ly if pit-bull mixes are included in the estimate, for despite going unregistered and uncounted, the pit bull has achieved near omnipresence in big cities and even a certain hard-won popularity in the suburbs. But at the same time, it has become less a type of dog than a strain of dog that still makes many Americans deeply uncomfortable. The demographic shifts that are transforming America’s human population find a mirror in the demographic shifts that are transforming America’s canine one, with the same effect: More and more we become what we somehow can’t abide. We might accept pit bulls personally, but America still doesn’t accept them institutionally, where it counts; indeed, apartment complexes and insurance companies are arrayed in force against them. And so are we: For although we adopt them by the thousands, we aban don them by the millions. The ever-expanding population of dogs considered pit bulls feeds an ever-expanding population of dogs condemned as pit bulls, and we resolve this rising demographic pressure in the way to which we’ve become accustomed: in secret, and in staggering numbers. We have always counted on our dogs to tell us who we are. But what pit bulls tell us is that who we think we are is increasingly at odds with what we’ve turned out to be.