First place, Portrait. Three flat-coated retrievers – Crew, Darcie and Pagan – by Carol Durrant from the UK. (Photo by Carol Durrant/Dog Photographer of the Year 2018)

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.

Cat-Friend vs Dog-Friend, Two Humans Acting Like House Pets

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)

Mushers and their huskies practice at a forest course ahead of the Aviemore Sled Dog Rally on January 24, 2016 in Feshiebridge, Scotland. Huskies and sledders prepare ahead of the Siberian Husky Club of Great Britain 34th race taking place at Loch Morlich this weekend near Aviemore. (Photo by Jeff J. Mitchell/Getty Images)

A dog and its owner perform a routine in the main arena on Day three of Crufts at the Birmingham NEC Arena on March 10, 2012 in Birmingham, England. (Photo by Dan Kitwood/Getty Images)

David Shrigley's new exhibition “Brain Activity” opens at the Hayward Gallery in London, England. Known for his crude and comedic observations Shrigley's “Brain Activity” is the first major survey of his work and will run from February 1 to May 13, 2012.

Photo: A taxidermied artwork of a Jack Russell dog entitled “I'm Dead”.

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.