Elfyn Evans of Great Britain and Daniel Barritt of Great Britain compete in their M-Sport WRT Ford Fiesta RS WRC during Day One of the WRC Australia on September 11, 2015 in Coffs Harbour, Australia. (Photo by Massimo Bettiol/Getty Images)

Elderly people attend an aquatic exercise at a private pool in Bangkok, Thailand, April 28, 2016. Many Thai families look after elderly relatives at a cost that countrywide adds up to just under a third of household income. The number of families facing this issue will balloon as the population ages at a rate among the fastest in Southeast Asia. (Photo by Athit Perawongmetha/Reuters)

Students exercise in body training at Bishan Vocational Education Center in Chongqing, southwest China, January 13, 2016. These students were trained to be stewardesses of the high-speed train. (Photo by Xie Jie/Xinhua)

A woman rides a donkey during a donkey race in Roum village, Jizeen countryside, southern Lebanon, August 9, 2015. (Photo by Ali Hashisho/Reuters)

A woman eats candy in the shape of a phallus during the Kanamara Matsuri, or Iron Phallus Festival through a street near the Kanamara shrine in Kawasaki outside of Tokyo April 5, 2015. The festival celebrates fertility and is used to raise awareness and money for the prevention of sexually transmitted diseases. (Photo by Thomas Peter/Reuters)

Tourists take pictures of straw figurines of traditional deities Shennong (R) and Zhang Wulang (L back) during China's National Day Holiday, in Xinhua county, Hunan province, October 4, 2015. (Photo by Reuters/China Daily)

An Alitalia plane approaches to land as starlings fly at Fiumicino international airport in Rome October 14, 2013. Italy will have to notify a planned government-led 500-million-euro bailout of near-bankrupt airline Alitalia to EU regulators who will then assess whether the measure complies with EU state aid rules, the European Commission said on Monday. (Photo by Max Rossi /Reuters)

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.