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.

Racegoers make their way home after Ladies Day on the second day of the Grand National meeting at Aintree Racecourse on April 9, 2010 in Aintree, England. Friday is traditionally Ladies day at the three-day meeting of the world famous Grand National, where fashion is as important as the racing. (Photo by Christopher Furlong/Getty Images)

“The Six-Day War or June War, also known as the 1967 Arab-Israeli War or the Third Arab-Israeli War, was fought between June 5 and June 10, 1967, by Israel and the neighboring states of Egypt (known then as the United Arab Republic [UAR]), Jordan, and Syria. The war began with a large-scale surprise air strike by Israel on Egypt. The outcome was a swift and decisive Israeli victory. Israel took effective control of the Gaza Strip and the Sinai Peninsula from Egypt, the West Bank and East Jerusalem from Jordan, and the Golan Heights from Syria. Opinions are divided on whether Israel's attack was an act of aggression or a preemptive strike of a defensive nature”. – Wikipedia

Photo: The corpse of a soldier lying on the line of the Israeli advance into Syria during the Six-Day War. (Photo by Terry Fincher/Getty Images). 1967

Female Chimpanzee “Fifi” eats carrots as she sits in her enclosure at Taronga Zoo on her 60th birthday May 21, 2007 in Sydney, Australia. Fifi is the oldest of the Zoo's chimp population, which consists of 19 individuals. (Photo by Ian Waldie/Getty Images)

Kieron Connolly’s new book of photographs of more than 100 once-busy and often elegant buildings gives an idea of how the world might look if humankind disappeared. Here: Bodie, Mono County, California. Gold was discovered at Bodie in 1859 (just after the initial California gold rush) and it went from mining camp to boomtown. Its decline began in 1880, when word spread of new boomtowns elsewhere. The Standard Consolidated Mine closed in 1913, and four years later the Bodie Railway was abandoned. By 1940 the population was down to 40. Today, Bodie is maintained in a state of arrested decay as a visitor attraction. (Photo by Alamy Stock Photo)

Ukraine's Ruslana performs her song Wild Dance ands wins the Eurovision Song Contest on May 15, 2004 at the Abdi Ipekci Stadium, in Istanbul, Turkey. The event – hosted by last year's winners Turkey – also celebrates the 30th Anniversary of ABBA's win. (Photo by Christopher Furlong/Getty Images)

“The Eton wall game is a game similar to football and Rugby Union, that originated from and is still played at Eton College. It is played on a strip of ground 5 metres wide and 110 metres long next to a slightly curved brick wall, erected in 1717”. – Wikipedia

Photo: The “Collegers” and the “Oppidans” of Eton College take part in the “Wall Game” as boys in their traditional school uniform watch from on top of the wall on November 17, 2007 in Eton, near Windsor, Berkshire, England. The first recorded “Wall Game” took place in 1766 with competition between the two houses at the boarding school remaining as fierce as ever on the annual St. Andrew's day event. The object of the game is to get the ball to either end of the wall and score a goal, which has not happened since 1909. As well as scoring a goal the players can win points with a “shy”, where the ball is held against the wall and touched by the hand and awarded one point. (Photo by Christopher Furlong/Getty Images)

Artist Joe Hill poses on his 3D artwork, from the “Joe and Max” project as part of an advertising campaign, during its presentation at a park in Moscow, Russia, July 4, 2015. (Photo by Sergei Karpukhin/Reuters)