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 giant sculpture of a seven-month-old baby by artist Marc Quinn entitled “Planet” contrasts against the stately grandeur of Chatsworth House and the Derbyshire countryside on 4 September, 2008, Chatsworth, England. The bronze sculpture painted white is part of the Beyond Limits exhibition of modern and contemporary sculpture displayed in the gardens of Chatsworth by Sotherby's. More than 20 works will be on display from 9 September to 2 November 2008. In past years acclaimed artists Damien Hirst, Antony Gormley, Salvador Dali and Henry Moore have had work exhibited. (Photo by Christopher Furlong/Getty Images)

In this handout from the Ministry of Defence, Royal Air Force VC10 and Tristar air-to-air refuelling aircraft support the first UK air combat mission in support of UN Resolution 1973 in flight on March 19, 2011. Col Muammar Gaddafi has vowed a “long war” against the “crusader aggression” after over 100 missiles were fired by the US and UK, during multi-national action aimed at enforcing a UN-mandated no-fly zone. (Photo by SAC Neil Chapman/MoD via Getty Images)

A three month-old baby gorilla named Hasani sits in the grass March 11, 2009 at the San Francisco Zoo in San Francisco, California. The newborn gorilla was given the name Hasani. Hasani's father, a twenty seven year-old gorilla named Oscar Jonsey, picked between five color coded cantaloupes representing the five name finalists to come up with the newborn's name that was submitted by Amanda VerPloeg of Oskaloosa, Iowa. (Photo by Justin Sullivan/Getty Images)

Japan Self-Defense Force members pay their respect to unidentified earthquake victims in vehicles during a mess funeral on April 8, 2011 in Yamamoto, Miyagi Prefecture, Japan. The 9.0 magnitude strong earthquake struck offshore on March 11 at 2:46pm local time, triggering a tsunami wave of up to ten metres which engulfed large parts of north-eastern Japan, and also damaging the Fukushima nuclear plant and threatening a nuclear catastrophe. The death toll continues to rise with numbers of dead and missing exceeding 20,000 in a tragedy not seen since World War II in Japan. (Photo by Athit Perawongmetha/Getty Images)

“The pygmy hippopotamus (Choeropsis liberiensis or Hexaprotodon liberiensis) is a large mammal native to the forests and swamps of western Africa (the specific name liberiensis means “of Liberia”, as this is where the vast majority live). The pygmy hippo is reclusive and nocturnal. It is one of only two extant species in the Hippopotamidae family, the other being its much larger cousin the common hippopotamus”. – Wikipedia

Photo: Monifa, a one month old baby Pygmy Hippopotamus takes a morning bath at Taronga Zoo on November 7, 2008 in Sydney, Australia. Monifa is the first Pygmy Hippopotamus to be born at Taronga Zoo in the past twenty three years. (Photo by Sergio Dionisio/Getty Images)

A Haka is performed before the ceremonial departure of the 'vaka' or traditional canoes ahead of their cross-Pacific voyage from Viaduct Harbour on April 13, 2011 in Auckland, New Zealand. Powered by sun and wind only, the 15,000 nautical mile journey to Hawaii via French Polynesia will set off on April 15, aiming to raise awareness of environmental issues such as ocean noise pollution, acidification and anoxic waters, whilst recapturing traditional Pacific voyaging. The votyage is named “Te Mana o Te Moana” meaning “The Spirit of the Sea”. (Photo by Phil Walter/Getty Images)