U.S. Army Sgt. 1st Class Anthony Heck and his military working dog, Nina 3, canvass an area while on patrol during Operation Marble Lion in Afghanistan's Jani Khel district, April 11, 2012. Heck is a military working dog handler assigned to Company C, 3rd Battalion, 509th Infantry Regiment. U.S. Army Sgt. 1st Class Anthony Heck and his military working dog, Nina 3, canvass an area while on patrol during Operation Marble Lion in Afghanistan's Jani Khel district, April 11, 2012. Heck is a military working dog handler assigned to Company C, 3rd Battalion, 509th Infantry Regiment. SHARE: Download: Full Size (1.99 MB) Tags: Photo Essays Credit: VIRIN: 165996-S-INV91-396.jpg Photo Gallery