Runners gather at the start line for the annual “Santa Speedo Run”, a charity race through the streets of the Back Bay neighborhood of Boston. (Photo by Gretchen Ertl/Reuters)

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.

A vendor (C) cuts slaughtered dogs for sale at his roadside stall in Duong Noi village, outside Hanoi December 16, 2011. While animal rights activists have condemned eating dog meat as cruel treatment of the animals, it is still an accepted popular delicacy for some Vietnamese, as well in some other Asian countries. Duong Noi is well-known as a dog-meat village, where hundreds of dogs are killed each day for sale as popular traditional food. Dog-eating as a custom is rooted in Vietnam and was developed as a result of poverty. One kilogram of dog meat costs about 130,000 dongs ($6.2). (Photo by Reuters/Kham)

A woman waters the plants outside her house in an alley at a slum in Mumbai October 28, 2014. (Photo by Danish Siddiqui/Reuters)

Deputies in the Ukrainian parliament brawled in the chamber on Tuesday, April 8, 2014 after a communist leader accused nationalists of playing into the hands of Russia by adopting extreme tactics early in the Ukrainian crisis. Two deputies from the Svoboda far-right nationalist party took exception to the charges by communist Petro Symonenko and seized him while he was talking from the rostrum. (Photo by Valentyn Ogirenko/Reuters)

Two sculputures at the waterfront in Marseille – Ever feel like youve forgotten something? No its not a mind trick – these are the amazing photos of sculptures done by a French artist. The sculptures are the work of Bruno Catalano and might look like theyre missing vital organs but the invisible bodies represent a world citizen according to their creator. (Photo by Caters News Agency)

Chinese female weightlifter Xiang Yanmei, who competes in the 69 kg weightclass, rests with a weight on her stomach as she checks her phone during a training session in preparation for the Rio Olympics at the Training Center of General Administration of Sports in China on July 20, 2016 in Beijing, China. Xiang Yanmei won the World Championships in 2013 and 2015. (Photo by Kevin Frayer/Getty Images)

“Life-size humanoid robot BERTI (Bristol EluMotion Robotic Torso number 1 or RT-1) is a self contained, fully automated Robotic Torso, designed and built by Elumotion to provide a robotic platform based on human anatomy. RT-1 is a highly articulated manipulating platform and includes novel dexterous hands that allow emulation of human gesturing”. – Elumotion.com

Photo: BERTI the robot interacts with a Sony AIBO robot dog at The Science Museum's Antenna Gallery on February 17, 2009 in London. (Photo by Peter Macdiarmid/Getty Images)