A participant poses with his laptop during the 33rd Chaos Communication Congress on its opening day on December 27, 2016 in Hamburg, Germany. The annual event is bringing together 12,000 computer hackers and activists who will meet over the next four days to share expertise and discuss topics related to the society and the digital world. (Photo by Morris MacMatzen/Getty Images)

Iraqi army soldiers fire mortars against the Islamic State militants, at Shahrazad village 2 miles (3 kilometers) east of Mosul, Iraq, Monday, November 14, 2016. A suicide bombing in Iraq targeted the Shiite sacred city of Karbala on Monday, killing at least six civilians, the latest attempt by the Islamic State group to distract from the government forces' offensive on the IS-held northern city of Mosul. (Photo by Hussein Malla/AP Photo)

Throughout the course of the long war in Afghanistan, Coalition troops have relied on thousands of military working dogs to help keep them safe, and make their jobs easier. The dogs are trained to detect explosives, to find illegal drugs, to search for missing comrades, or target enemy combatants. Not only are they active on the front lines, but behind the lines they serve as therapy dogs, service dogs, and loyal companions. They also share the same risks as the ground troops, suffering injuries and sometimes death on the battlefields. Gathered here are images of these dogs and their handlers in Afghanistan and back home, from over the past several years, part of the ongoing series here on Afghanistan.

A worker distributes electronic waste at a government managed recycling centre at the township of Guiyu in China's southern Guangdong province June 10, 2015. The town of Guiyu in the economic powerhouse of Guangdong province in China has long been known as one of the world’s largest electronic waste dump sites. At its peak, some 5,000 workshops in the village recycle 15,000 tonnes of waste daily including hard drives, mobile phones, computer screens and computers shipped in from across the world. (Photo by Tyrone Siu/Reuters)

A veterinarian kisses an 8-month-old cat, wearing a prosthetic two-wheel device, at a veterinary hospital in Chongqing municipality, March 16, 2015. The cat's rear legs lost the abilty to walk after falling from the ninth to fifth floor of a building last November, its since undergone four major surgeries which included removing parts of its organs, local media reported. (Photo by Reuters/China Daily)

New York Sports Club Gets In The Election Spirit With Hillary Clinton And Donald Trump Boxing Inspired Class on October 27, 2016 in New York City. (Photo by Thos Robinson/Getty Images for DKC for New York Sports Clubs)

A worker lifts up tiles during a bodybuilding contest for tile factory workers as part of celebrating Indonesia Independence day at Jatiwangi village in Majalengka, Indonesia West Java province, August 11, 2017. Indonesia Independence day is on August 17, 2017. (Photo by Reuters/Beawiharta)

Filipinos riding on makeshift carts cross over an overflowing dam during a downpour in Las Pinas city, south of Manila, Philippines, 05 September 2017. According to the latest forecast from the Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) state weather bureau, typhoon signals were raised over Northern Luzon brought by a tropical storm (local name: Tropical Storm Kiko) and warned fisherfolks and small seacrafts not to venture onto the sea due to big waves. (Photo by Francis R. Malasig/EPA/EFE)