I read about a book on another blog and did a little searchin' around to discover this is a well-reviewed novel that sounded very interesting - Lean on Pete by Willy Vlautin. It's gong to be published in the U.S. in April (it was released in the U.K. in February).
From the publisher's website:
Fifteen-year-old Charley Thompson wants a home, food on the table, and a high school he can attend for more than part of a year. But as the son of a single father working in warehouses across the Pacific Northwest, Charley's been pretty much on his own. When tragic events leave him homeless weeks after their move to Portland, Oregon, Charley seeks refuge in the tack room of a run-down horse track. Charley's only comforts are his friendship with a failing racehorse named Lean on Pete and a photograph of his only known relative. In an increasingly desperate circumstance, Charley will head east, hoping to find his aunt who had once lived a thousand miles away in Wyoming—but the journey to find her will be a perilous one.
In Vlautin's third novel, Lean on Pete, he reveals the lives and choices of American youth like Charley Thompson who were failed by those meant to protect them and who were never allowed the chance to just be a kid.