Britain's biggest dog, 18 month old great Dane, Freddy seen realxing on the sofa with it's owner Claire Stoneman at their home in Southend-on-Sea, Essex, England. (Photo by Matt Writtle/Barcroft Media)

A woman sits with a Great Dane during the first day of the Crufts dog show in Birmingham, central England March 6, 2014. (Photo by Darren Staples/Reuters)

Evelyn Ramirez and Juan Manuel enjoy posting adorable photos of their pit bull on Instagram. However, their photos seem to be gaining traction online, thanks to their pet’s dapper get-ups.

Spunky runs during the third heat of a dog race Monday, September 1, 2014, at Canterbury Park, in Shakopee, Minn. Canterbury Park hosted their annual Labor Day Wiener Dog Wars in which dogs competed in seven races on the horse track for the title of Grand Champion. (Photo by Jeff Wheeler/AP Photo/The Star Tribune)

Photographer Lucy Ray says she has been scratched by the pooches who are diving underwater to try and catch a tennis ball. Their wide-eyed desperation has been captured by a specialist underwater photographer who admits she has been bitten and scratched by the pooches who only had eyes for the ball. Lucy Ray, 34, said: “A dog could have the cutest face on land but as soon as they get in the water they can be terrifying. Their eyes bulge and teeth shoot out of their mouth just like an alien as they try to catch the ball”. (Photo by Lucy Ray)

A Yorkshire Terrier has it's hair done on a grooming table on Day one of Crufts at the Birmingham NEC Arena on March 8, 2012 in Birmingham, England. During the annual four-day competition nearly 22,000 dogs and their owners will compete in a variety of categories, ultimately seeking the coveted prize of “Best In Show”. (Photo by Dan Kitwood/Getty Images)

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.