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.

Transgender Kendra Ferrari, 21, performs during Miss Night Queen beauty contest in Guatemala City, Friday, June 15, 2012. Ferrari won the pageant and will represent the transgender community for one year. (Photo by Rodrigo Abd/AP Photo)

A hot air balloon floats over farm fields south of Washington, Ill., as the sun slips behind clouds on the autumn afternoon of Wednesday, September 24, 2014. (Photo by Ron Johnson/AP Photo/Peoria Journal Star)

Professional conceptual category winner. Greetings from Mars, by Julien Mauve, France. Mauve says: “I have always wondered what it would be like to discover a totally different world ... and to photograph it for the first time as if I was Ansel Adams. So I came up with this project, which is about space exploration and discovery. But it’s also about our behavior in front of landscapes and how we create pictures that will share our personal story with the world”. (Photo by Julien Mauve)

People look at damaged trees after a tornado hit Funing on Thursday, in Yancheng, Jiangsu province, China June 24, 2016. (Photo by Aly Song/Reuters)

A boy looks for scrap metal using an improvised magnetic tool near a construction site in New Delhi, India, March 21, 2016. (Photo by Cathal McNaughton/Reuters)

Yala national park, Sri Lanka. Category: Action. “The daylight was fading and I was scanning the bush for a leopard. Then, I saw this garden lizard and a common bronzeback snake in the road. When the snake struck, the lizard performed amazing acrobatics to avoid it. The snake didn’t enjoy the extra attention from the crowd of jeeps. The distraction gave the lizard the chance to live another day”. (Photo by Sajith Buddikha Withanage/National Geographic Traveller UK)

In this January 24, 2017 photo, boxer Idamerys Moreno wraps a bandage on her hand before a training session at a sports center in Havana, Cuba. Boxing has long been an athletic engine for Cuba, which has won 72 Olympic medals in that category but women are not allowed to box. (Photo by Ramon Espinosa/AP Photo)