Opposition students march against Venezuelan President Nicolas Maduro's government in Caracas February 12, 2015. Venezuelan troops blocked students during marches against Maduro on Thursday as pro-government supporters also rallied on the anniversary of 2014 protests that led to 43 deaths. In Caracas, troops cordoned off scores of students on an unauthorized march to a church where they planned a mass in honour of demonstrators who died. (Photo by Jorge Silva/Reuters)

In this May 21, 2021, file photo, JoJo Hamner, a cast member of the “Sexxy After Dark: Where Dinner Meets Play” show, gets the Pfizer COVID-19 vaccine during a pop-up vaccine clinic at Larry Flynt's Hustler Club in Las Vegas. It's one of several methods health officials are employing here and across the country to bring vaccines directly to people to counter waning demand. In tiny towns, ballparks, strip clubs, and marijuana dispensaries, officials are setting up shop and offering incentives to entice people who so far have not gotten shots. (Photo by Ellen Schmidt/Las Vegas Review-Journal via AP Photo/File)

A man helps an elderly woman to run for cover after heavy shelling on the only escape route used by locals, while Russian troops advance towards the capital, in Irpin, near Kyiv, Ukraine on March 6, 2022. (Photo by Carlos Barria/Reuters)

Volodymyr, a service member of the Ukrainian armed forces, plays with puppies at fighting positions on the line of separation from pro-Russian rebels in Donetsk region, Ukraine on April 10, 2021. The two unnamed puppies living on frontline positions will be taken home and named by soldiers departing on troops rotation. (Photo by Oleksandr Klymenko/Reuters)

Japanese chorus girls appear to be drilling in military tactics atop their theater building as they perform salutes, June 30, 1937. The officer is from the Japanese regular army and says the girls display more rhythm in their drills than do the regular troops. (Photo by AP Photo)

U.S. Army helicopters providing support for U.S. ground troops fly into a staging area fifty miles northeast of Saigon, Vietnam, August 28, 1966. Helicopter fuel is stored in the large rubber tanks, foreground. (Photo by Henri Huet/AP Photo)

British-based Ukrainians gather outside the Russian Embassy in London to protest against the build-up of troops in the Crimea region, on March 2, 2014. The demonstrators chanted and held banners demanding “Hands off Ukraine”. (Photo by John Stillwell/PA Wire)

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.