Healing Holt by Shannon Nemechek

Holt Lawson had to grow up quick after his father was killed in action while serving in the Army. His mother had begged him not to follow in his father’s footsteps, but it had been his dream for as long as he could remember. Now he is off to Afghanistan with his new K-9 partner Gunner and leaving behind his family and the girl next door Aspen, who had held his heart the moment he met her.
Aspen Knight grew up next door, next door to her best friend, Jules and her big brother Holt, her childhood crush. Her love of animals tended to get her into trouble and Holt had always been her savior especially when she found herself in another awkward situation. Now she’s all grown up and giving back the only way she knows- training rescues for the Healing Heroes.
When Aspen gets a lead on a dog fighting ring, she springs into action, but trouble finds her and now her life, as well as the lives of the dogs she’s sworn to protect hangs in the balance. Her only hope is if Holt can get to them in time.