A worker inspects the Christ the Redeemer statue which was damaged during lightning storms in Rio de Janeiro January 21, 2014. (Photo by Severino Silva/Reuters/Agência o Dia)

Thai office workers walk past armed soldiers standing guard outside the Shinawatra Tower Two in Bangkok, Thailand, 20 May 2014. Thai army Chief Prayuth Chan-ocha early on 20 May 2014, declared martial law giving the military full control to prevent further protest-related violence in the country. The statement was issued about 3 am on 20 May (2000 GMT), according to local media reports. Prayuth has the authority to declare martial law without the consent of the government, which has had caretaker status since 09 December 2013. Thailand has been wracked by six months of non-stop protests seeking to topple the government. At least 25 people have died in political-related violence and more than 700 injured. (Photo by Narong Sangnak/EPA)

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.

Sellers sort persimmons for sale at a wholesale market in Hanoi, Vietnam October 3, 2016. (Photo by Reuters/Kham)

Cocoa Beach, Florida, USA. 7th October, 2016. Kaleigh Black, 14, left, and Amber Olsen, 12, run for cover as a squall with rain and wind pelt them while they explore the Cocoa Beach Pier on Friday (10/7/16) after hurricane Matthew passed to the east on Florida's east coast.(Photo by Douglas R. Clifford/Tampa Bay Times/ZUMA Wire/Alamy Live News)

Models wait backstage during Ukrainian Fashion Week in Kiev, Ukraine, October 12, 2016. (Photo by Gleb Garanich/Reuters)

Drunk fresher is helped by students as she falls to the ground on night out at during the alcohol-fuelled Freshers’ Week in Birmingham, United Kingdom on September 18, 2017. Freshers are inducted during Freshers' Week – the first week of the Academic year – one of the busiest and most fun weeks of the year. (Photo by Caters News Agency)

Trees are reflected on the surface of a lake in the Okefenokee swamp lands in Georgia, USA on October 21, 2017. (Photo by Chris Moore/Solent News & Photo Agency)