A weary-looking man stands at an intersection, backpack at his feet. Curled up nearby is a mixed-breed dog, unfazed by the passing traffic. The man holds a sign that reads, "Two old dogs need help. God bless." What's happening here? Leslie Irvine breaks new ground in the study of homelessness by investigating the frequently noticed, yet underexplored, role that animals play in the lives of homeless people. Irvine conducted interviews on streetcorners,...