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)

A giant new exhibition space created by famed graffiti artist Banksy opens to the public on May 3, 2008 in London, England. The disused tunnel beneath Waterloo station has been transformed by 30 artists from around the world. The three day event, tagged as the “Cans festival”, also invites the public to add their own stencil art. (Photo by Jim Dyson/Getty Images)

Wadha al-Sayyed, wife of captive Lebanese soldier Khaled Moqbel, protests for his release and government action, near burning tyres blocking a road in Beirut, December 15, 2014. More than two dozen members of the Lebanese security forces are being held by Sunni Islamists. (Photo by Hasan Shaaban/Reuters)

In this photo taken on Monday, January 5, 2015, a mallard duck attempts to walk on a frozen pond in Yukon, Okla. (Photo by Steve Gooch/AP Photo/The Oklahoman)

Pedestrians have a snowball fight in Times Square following a mandatory shutdown of the streets at 11 p.m. on January 26, 2015 in New York City. New York, and much of the Northeast, is bracing for a major winter storm which is expected to bring blizzard conditions and 10 to 30 inches of snow to the area. (Photo by Alex Trautwig/AFP Photo)