A Military Working Dog plays with Staff Sgt. Stephanie Pecovsky, 11th Security Forces Group MWD trainer, while taking a break during a ruck march Aug. 8, 2012 at Joint Base Andrews, Md. The Airmen are getting the MWD acclimated to walking long distances and still performing their duties, before they are deployed downrange. (U.S. Air Force photo/Senior Airman Perry Aston)