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.

Dr. P.A. Smithe was sent by the American Red Cross as a doctor and surgeon to work at a hospital in Vienna. He sailed to Europe in December 1915 and returned home in August 1916, according to his daughter, who donated his images to the National World War I Museum. Photo: Turkish army, including cavalry, infantry and artillery. (Photo by Dr. P.A. Smithe/National World War I Museum, Kansas City, Mo.)

Hong Kong art gallery director Sarah Greene said that Wolf, known for his work depicting mega-cities, has died Tuesday, April 24, 2019 night at his home. She said he was 64. Wolf won first prize in the World Press Photo competition in 2005 and 2010. Here: Architecture of Density #119, 2009. (Photo by Michael Wolf, courtesy of Flowers Gallery)

This Hawaiian cat sanctuary has created an “island paradise” for the state’s stray cats. Although most people would take a trip to one of the Hawaiian Islands’ many heavenly sights, Andrew Marttila, 32, and his partner, Hannah Shaw, 30, wanted to visit something more unusual. They decided to take a trip to the Lanai Cat Sanctuary, which is currently home to more than 500 felines. Here: Kitten Lady, 30, is surrounded by rescued cats at the the Lanai Cat Sanctuary in Hawaii. (Photo by Andrew Marttila/Caters News Agency)

A volcanic eruption at Mount Etna’s Vorgaine crater in Sicily, Italy on December 3, 2015. (Photo by Marco Restivo/Barcroft Media)

A man rides a horse at a playground on a hill in Kabul April 19, 2015. (Photo by Mohammad Ismail/Reuters)

A farmer rides a truck in a village near Nong Khai, Thailand, September 16, 2015. (Photo by Jorge Silva/Reuters)