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.

Reveller Jacqueline Fernandez looks on in the rain during the 26th Annual Kensington Market Winter Solstice Parade in Toronto, Canada, December 21, 2015. (Photo by Mark Blinch/Reuters)

A Republican farmer defending a farm on the outskirts of Irun against Nationalist forces during the Spanish Civil War, 6th September 1936. A comrade lies dead by his side. (Photo by Keystone/Hulton Archive/Getty Images)

A model walks down the runway during the Safilo fashion show at the Mercedes-Benz Fashion Pavilion on January 30, 2012 in Stockholm, Sweden. (Photo by Ian Gavan/Getty Images)

A model walks the runway during the Craig Lawrence show at London Fashion Week Autumn/Winter 2012 at Somerset House on February 19, 2012 in London, England. (Photo by Stuart Wilson/Getty Images)

Julia Zlobina and Alexei Sitnikov of Azerbaijan gesture as they wait in the results area after competing in the ice dance free dance figure skating finals at the Iceberg Skating Palace during the 2014 Winter Olympics, Monday, February 17, 2014, in Sochi, Russia. (Photo by Vadim Ghirda/AP Photo)

Performers line up during the closing ceremony of the 2014 Winter Olympics, Sunday, February 23, 2014, in Sochi, Russia. (Photo by Darron Cummings/AP Photo)

A sign reading “STOP Danger of Avalanches” blocks a local road on January 11, 2012 near Ischgl, Austria. Over the last few days heavy snowfalls have caused chaos in parts of Austria and Switzerland by blocking rail and road connections, stranding vacationers at mountain ski resorts and creating the risk of avalanches throughout the region. (Photo by Johannes Simon/Getty Images)