Suspect by Robert Crais

Maggie is a bomb-sniffing dog with the military in Afghanistan. Scott James is an LA cop who barely survived a shoot-out. Both are suffering from post traumatic stress disorder. The story of their bonding and Scott's attempts to figure out who shot him and his partner make for a riveting tale. Even if you're not a dog lover, you can't help but love the fiercely loyal Maggie, who will do anything to protect her human. Suspect is a such a page turner that I read the whole thing in one day.