After returning from a deployment to Iraq In 2007, Cartwright volunteered to become a canine handler. He was partnered with Isaac, a black Labrador Retriever, at the Military Working Dog Program or “Dog School” at Ft. Leonard Wood in Missouri. The two became a close-knit team after completing the five-and-a-half month training program. Since then, Cartwright and Isaac have served two tours of duty in Afghanistan locating explosive devices planted by terrorists near roads, hospitals, schools and military facilities.