Ugly dog contestants Sweepee Rambo and owner Jason Wurtz celebrate in winning the 2016 World's Ugliest Dog Contest at the Sonoma-Marin Fair in Petaluma, California, USA, 24 June 2016. (Photo by Peter Dasilva/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.

Disabled dogs outfitted with wheelchairs walk at an animal rescue center on July 12, 2008 in Chengdu of Sichuan Province, China. The center has adopted over 100 stray dogs and cats from quake-struck areas. Those who were hurt or disabled are outfitted with a cart to help support they're body and make them mobile. (Photo by China Photos/Getty Images)

Workers prepare Koshary, a popular Egyptian dish, in an attempt to break the Guinness World Record for the world's biggest plate of Koshary, at a general garden in Zamalek, Cairo, January 17, 2015. Koshary is a traditional Egyptian dish dating to the 19th century in which rice, pasta and lentils are mixed together in one plate with a topping of spicey tomato sauce and some crispy fried onions. With a huge plate of koshary measuring 10 metres long and in width and of 1.2 metres in height, the plate weighed 7 tonnes, or about 7,000 kg. About 6,000 attendees turned up to the festival, earning it a place in the world record books. (Photo by Mohamed Abd El Ghany/Reuters)

People pray inside a temple at the Janmashtami Hindu Festival at Bhaktivedanta Manor on August 22, 2011 in Watford, England. Up to 72,000 were expected to take part in the two day festival celebrating the birth of Krishna, in what is believed to be the largest Hindu festival gathering outside of India. (Photo by Dan Kitwood/Getty Images)

Members of the Gremlins Carnival Club, open the doors to their workshop to unveil for the first time their cart, Jungle Drums, which is their entry to this year's Bridgwater Carnival, on November 4, 2011 in Bridgwater, England. (Photo by Matt Cardy/Getty Images)

A police officer jump ropes with a police dog at a police dog training base on July 11, 2011 in Beijing, China. The Police Dog Training Base was opened to a media visit to show the dogs skills to the public. (Photo by ChinaFotoPress/Getty Images)