American singer Bleta “Bebe” Rexha poses with fans at the iHeartRadio MuchMusic Video Awards (MMVAs) in Toronto, Ontario, Canada on August 26, 2018. (Photo by Mark Blinch/Reuters)

Taylor Swift arrives at the American Music Awards on Tuesday, October 9, 2018, at the Microsoft Theater in Los Angeles. (Photo by Mike Blake/Reuters)

British sprinter Dina Asher-Smith arrives at The Fashion Awards 2018 In Partnership With Swarovski at Royal Albert Hall on December 10, 2018 in London, England. (Photo by Mike Marsland/BFC/Mike Marsland/Getty Images)

Actor Candis Cayne performs at John Varvatos + OUT Support the Gay Men's Chorus of LA on September 29, 2016 in Los Angeles, California. (Photo by Matt Winkelmeyer/Getty Images for John Varvatos)

Girls hold hands as they help each other wade through a flooded street after the passing of Hurricane Matthew in Les Cayes, Haiti, Thursday, October 6, 2016. Two days after the storm rampaged across the country's remote southwestern peninsula, authorities and aid workers still lack a clear picture of what they fear is the country's biggest disaster in years. (Photo by Dieu Nalio Chery/AP Photo)

The selfie is the most popular photography trend of the internet today. It's gotten so popular, in fact, that even our beloved feline friends have started to catch on. I dare you to keep the smile off your face for this one!

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.