A protester from the People for the Ethical Treatment of Animals (PETA) displays a placard from a bathtub as a people looks on during a demonstration to call on the public to eat more vegetables to save water, in Sao Paulo on August 2, 2016. (Photo by Cris Faga via ZUMA Wire)

A dune buggy driver trains before competing in a sand dune drag racing event on January 8, 2016, as part of the Liwa 2016 Moreeb Dune Festival in the Liwa desert, some 250 kilometres southwest of Abu Dhabi. The festival, which attracts participants from around the Gulf region, includes a variety of races (cars, bikes, falcons, camels and horses) or other activities aimed at promoting the country's folklore. (Photo by Karim Sahib/AFP Photo)

A Poison Ivy and Boba Fet (Star Wars) cosplayer during the MCM Birmingham Comic Con at NEC Arena on March 18, 2017 in Birmingham, England. (Photo by Ollie Millington/Getty Images)

Heralds ride on horse-back through the streets of Moscow proclaiming the forthcoming coronation of Tsar Nicholas II, 1896. P.S. All pictures are presented in high resolution.

Miss Bahamas Celeste Marshall on stage at the 2012 Miss Universe National Costume Show on Friday, December 14, 2012 at PH Live in Las Vegas, Nevada. The 89 Miss Universe Contestants will compete for the Diamond Nexus Crown on December 19, 2012. (Photo by AP Photo/Miss Universe Organization L.P., LLLP)

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.

Norma Galicia aka “Pirulina” takes part in a demonstration during the commemoration of the International Day for the Elimination of Violence Against Women, in Guatemala City on November 25, 2013. So far this year, 696 women have died due to violent events in Guatemala. (Photo by Johan Ordonez/AFP Photo)

Couples take part in the “Love and Challenge Marathon” in Hanoi, Vietnam, 16 August 2015. Fifty couples, who are going to get married, participated in the event which is held the fifth time. This year, the winners of the marathon received a honeymoon trip to Malaysia. (Photo by Luong Thai Linh/EPA)