Duuk, 3rd Military Police Detachment explosives detection military working dog, receives his final goodbyes from Soldiers of the 3rd MP Det. after being adopted at Fort Eustis, Va., Sept. 9, 2013. MWDs usually serve up to 10 years before retiring, when they are then eligible for a screening process to be considered for adoption. (U.S. Air Force photo by Airman 1st Class Austin Harvill/Released)