Survivors #1: The Empty City - Erin Hunter - Bog

The time has come for dogs to rule the wild. Lucky has always been a Lone Dog, but when the Big Growl strikes, his whole world changes. With enemies at every turn, Lucky knows he can't survive on his own, and he falls in with a Pack. He's not sure he's ready to rely on other dogs?or have them depend on him?but in a dangerous new world, he may not have a choice.