Myouchin Munehisa, 44, as he finishes Hibashi iron bells made of iron on a production line at Myochin Honpo shop on April 25, 2014 in Himeji, Japan. Myochin family's iron business, started in the Heian period (794-1185) of Japan as an armor and helmet maker, shifted as the needs of people changed in the course of history. (Photo by Buddhika Weerasinghe/Getty Images)

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.

Women compare their bikini marks after sunbathing on a terrace to have the perfect bikini line (“marquinha” in Portuguese), at the Erika Bronze spa in Rio de Janeiro, Brazil, November 17, 2016. Women start arriving at the spa between 7am and 8am and will tan for approximately 3 hours. (Photo by Pilar Olivares/Reuters)

Revelers of the “Societe des Champs Elysee” launch fireworks before boarding the Rampart-St. Claude street car line, which just opened last fall, to commemorate the official start of Mardi Gras season, in New Orleans, Friday, January 6, 2017. (Photo by Gerald Herbert/AP Photo)

Female members of the Chinese People's Liberation Army (PLA) honour guard stand behind a string to ensure that they are in a straight line before a welcoming ceremony for Russian President Vladimir Putin outside the Great Hall of the People in Beijing, China, June 25, 2016. (Photo by Kim Kyung-Hoon/Reuters)

A worker manually changes the direction of the bonde, the typical tram line in Santa Teresa neighborhood, using a rope in Rio de Janeiro, Brazil, September 9, 2015. The Santa Teresa bonde, called “Bondinho” in Portuguese, is running with passengers as a part of a test period, after the service was suspended in 2011 following an accident that killed six people, according to residents. (Photo by Pilar Olivares/Reuters)

Prince William exchanges rings with his bride Catherine Middleton in front of the Archbishop of Canterbury Rowan Williams inside Westminster Abbey on April 29, 2011 in London, England. The marriage of Prince William, the second in line to the British throne, to Catherine Middleton is being held in London today. The marriage of the second in line to the British throne is to be led by the Archbishop of Canterbury and will be attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding. (Photo by Dominic Lipinski - WPA Pool/Getty Images)

People view artist David Byrne's installation "Tight Spot" beneath Manhattan's High Line park on September 27, 2011 in New York City. The 48-foot by 20-foot inflatable globe is squeezed beneath the steel support framework of the High Line and is accompanied with a rumbling audio soundtrack created by distorting Byrne's voice. (Photo by Mario Tama/Getty Images)