A drunk racegoer lays on the ground as her friend tries to wake her up during the Emirates Melbourne Cup Day held at Flemington Racecourse in Melbourne Australia, on November 4, 2014. (Photo by Asanka Brendon/Rex Features)

Competitors line up their boats for some formalities during the Aberdeen Dragon Boat Races. (Photo by Jessica Hromas)

Lindsay Heimbach goes airborne while sledding down a hill on Mt. Lemmon December 27, 2008. (Photo by James Gregg/Arizona Daily Star)

Peter Ver Ploeg carries Virginia Petrovek through the mud pit during the North American Wife Carrying Championship, Saturday, October 8, 2016, at the Sunday River Ski Resort in Newry, Maine. (Photo by Robert F. Bukaty/AP Photo)

A clown plays the violin during the XXI Convention of Clowns, at the Jimenez Rueda Theatre, in Mexico City, Mexico, October 19, 2016. In the wake of the creepy clown sightings in several states of North and South Americas and Europe that caused widespread panic, professional clowns from across Latin America came together at an annual convention in Mexico to give a serious message: “We are clowns, not killers!”. Around 200 clowns took part in the 21st International Clown Convention, dressed in bright coloured clothes and makeup, and chanted the word as they clicked group pictures to counter the “creepy clown” craze. (Photo by Carlos Jasso/Reuters)

Using body paint and a woodland like location, Gesine appears to have created a model to look just like a red panda, Dortmund, Germany, October, 2016. An artist brings animals to life using body paint and contorted models. At first glance, these images could be mistaken for portraits of wildlife in their natural habitat were created with paper and paint. However, they are actually the incredible works of illusion by talented body painter Gesine Marwedel, who paints models to creates realistic animals. (Photo by Gesine Marwedel/Barcroft Images)

The sun rises between Sgurr nan Gillean and Knight’s Peak, Black Cuillin, Isle of Skye. (Photo by Adrian Trendall/Mountain Photo of the Year)

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.