A woman looks at photographs of dogs to choose a pet to rent at Puppy The World on January 24, 2009 in Tokyo, Japan. Rent-a-dog is becoming increasingly popular amongst people who love dogs but are unable to look after a pet full time due to limited living space or long working hours. Customers pay the dog-rental outlet around 2500 yen (32.5 USD) for an hour, and usually take their rented pet for a walk along the nearby beach. (Photo by Junko Kimura/Getty Images)

A Husky dog looks on before a sled and skijoring race in the village of Kadnikovo outside Yekaterinburg, Russia, December 10, 2016. (Photo by Maxim Shemetov/Reuters)

A dog in a purple dress, taken in El Dorado, Arkansas, December 2016. The dapper dogs in clothes are back with a second series, and they’re feeling festive. (Photo by Tammy Swarek/Barcroft Images)

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)

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 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)

A dog sanctuary in Mexico is the first of its kind as it provides troubled canines with a safe and loving home. Milagros Caninos (Miracle Dogs) is a sanctuary in Mexico City that takes in abused, elderly, terminally ill, and disabled dogs.