"Dog Gone: A Lost Pet's Extraordinary Journey and the Family Who Brought Him Home" by Pauls Toutonghi (Knopf): There are lost dogs, and then there is Gonker, a 6-year-old golden retriever mix with Addison's disease. The beloved pet of Fielding Marshall, Gonker bolted into the woods while hiking on the Appalachian Trail with his owner in 1998. If Gonker isn't found within 23 days to receive another dose of artificial hormones, he will die. "Dog Gone" explores not only the search for Gonker, but also the pain — emotional and, in Marshall's case, physical — of losing a furry member of the family: "Maybe this is why their loss is so heartbreaking," Toutonghi writes of missing pets whose "attitude toward us is unquestioningly kind." "Their loss implies the loss of the kind of innocence that doesn't exist very often in our contemporary world."