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.

“The Portuguese Water Dog is a breed of working dog as classified by the American Kennel Club. Portuguese Water Dogs are originally from the Portuguese region of the Algarve, from where the breed expanded to all around Portugal's coast, where they were taught to herd fish into fishermen's nets, to retrieve lost tackle or broken nets, and to act as couriers from ship to ship, or ship to shore. Portuguese Water Dogs rode in bobbing fishing trawlers as they worked their way from the warm Atlantic waters of Portugal to the frigid fishing waters off the coast of Iceland where the fleets caught cod to bring home. Portuguese Water Dogs were often taken with sailors during the Portuguese discoveries”. – Wikipedia

Photo: Kix, a Portuguese Water Dog , enjoys a walk around the muddy fields near his home before the grooming and preparation starts for this years Crufts on March 3, 2009 in Telford, England. (Photo by Christopher Furlong/Getty Images)

On the streets of Kunming, Yunnan Province, you can find odd couple – a dog and a cat who sits on his four-legged companion. They are Vantsay and Mimi. The owner of animals, a 42-year-old retired policeman Xu Jin is surprised with so strong friendship. “When I got the dog, and I began to take her for a walk, the cat became plaintive, – says the man. – So I bought a leash and began to take her too. Soon, however, the cat began to tire and quickly realized that it is much easier to ride on the back of a dog. ”

Zappa, a toothless 15-year-old Italian greyhound that looks surprisingly like Sid the Sloth from the animated movie Ice Age, is redefining dog beauty. Owners Sadie and Rosalie Millen, of Pewaukee, Wisconsin, say that Zappa started sticking her tongue out a few years ago when she lost her teeth.