When I return home from a trip, or really from any absence longer than 15 minutes, my dog Taiga greets me with the canine equivalent of pyrotechnics: Leaping, writhing, twirling, lip curling, a quiver full of hyena sounds. Once, after a 13-day visit to Alaska, she reached my face in a single bound from the floor, her nose making high-speed contact with my mouth. Proof once again that love can draw blood—mostly metaphorical, sometimes literal.