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.

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.

Hungarian Puli sheep dog, Fee, jumps over a hurdle during a preview for a pedigree dog show in Dortmund on Thursday April 24, 2008. (Photo by Frank Augstein/AP Photo)

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. ”

Five-year-old Julian Becker and his 165 pound pet Newfoundland Max have been best buds around all their lives. To commemorate the friendship and to keep Julian's father, a Naval officer who is often away, in the loop, Julian's mom Stasha began taking photos. Photo: Hats off (or on) to Julian for sharing his blanket with his good buddy. Not that the furry beast needs it... (Photo by Stasha Becker/Rex Features)