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 prisoner from the Pedrinhas prison is carried to receive medical help after he was injured during a fight between rival gangs inside the jail, in Sao Luiz, capital of Maranhao state, January 8, 2014. The recent posting on a major Brazilian news website of a video filmed last December 17 by Pedrinhas prisoners of the decapitated and tortured bodies of rival inmates inside the jail has highlighted some of the problems present in the country's prison system which houses nearly twice as many prisoners as its capacity, according to official statistics. (Photo by Douglas Cunha/Reuters/O Estado do Maranhão)

Romanian military doctors and medical students sit on a bus behind steamy windows before the National Day parade in Bucharest, Romania, Thursday, December 1, 2016. Military planes and helicopters flew over the Romanian capital Thursday as thousands turned out to celebrate the national day, marking the date when the country reunified with Transylvania in 1918. (Photo by Vadim Ghirda/AP Photo)

A girl swims in floodwaters in Malaysia' s northeastern town of Rantau Panjang, which borders Thailand, on January 5, 2017 Floods in two northeast Malaysian states have now forced almost 23,000 people from their homes and extra relief centres have been opened, rescue officials said on January 4. (Photo by Mohd Rasfan/AFP Photo)

An urban fox walks alongside the Mall in central London, Britain, November 29, 2016. (Photo by Toby Melville/Reuters)

A twelve foot long giant hamster has surprised Londoners along the South Bank, Millennium Bridge and Clapham Common on May 26, 2016. A 4-metre pedal-powered mechanical model hamster, which has been created in the likeness of Jaffa the hamster, who is listed as one of the 10 oddest discoveries made by Kwik Fit technicians in customers’ cars. (Photo by Joe Pepler/Rex Features/Shutterstock)

A model presents a creation by Japanese designer Yoshikazu Yamagata for his label writtenafterwards during the Mercedes-Benz Fashion Week in Tokyo, Japan, 16 March 2016. The presentation of the Autumn/Winter 2016 collections runs from 14 to 19 March. (Photo by Kiyoshi Ota/EPA)

Participants take part in the annual Great Spitalfields Pancake Race in aid of London's Air Ambulance in London, Britain February 9, 2016. (Photo by Stefan Wermuth/Reuters)