“Photographer Seth Casteel has definitely taken animal photography to new heights – or depths – with his hilarious photos of dogs chasing balls underwater. Casteel, who, naturally, has two dogs of his own (a mini Labradoodle and a Norwich terrier), said that he's drawn to underwater dog photography because the photos show a side of dogs that people may have never seen before”.

Photo: Seth Casteel Underwater Dog Pictures (Photo by Seth Casteel)

A reveller takes part with her dogs in the annual halloween dog parade at Manhattan’s Tompkins Square Park in New York, U.S. October 22, 2016. (Photo by Eduardo Munoz/Reuters)

People pray inside a temple at the Janmashtami Hindu Festival at Bhaktivedanta Manor on August 22, 2011 in Watford, England. Up to 72,000 were expected to take part in the two day festival celebrating the birth of Krishna, in what is believed to be the largest Hindu festival gathering outside of India. (Photo by Dan Kitwood/Getty Images)

Members of the Gremlins Carnival Club, open the doors to their workshop to unveil for the first time their cart, Jungle Drums, which is their entry to this year's Bridgwater Carnival, on November 4, 2011 in Bridgwater, England. (Photo by Matt Cardy/Getty Images)

Workers prepare Koshary, a popular Egyptian dish, in an attempt to break the Guinness World Record for the world's biggest plate of Koshary, at a general garden in Zamalek, Cairo, January 17, 2015. Koshary is a traditional Egyptian dish dating to the 19th century in which rice, pasta and lentils are mixed together in one plate with a topping of spicey tomato sauce and some crispy fried onions. With a huge plate of koshary measuring 10 metres long and in width and of 1.2 metres in height, the plate weighed 7 tonnes, or about 7,000 kg. About 6,000 attendees turned up to the festival, earning it a place in the world record books. (Photo by Mohamed Abd El Ghany/Reuters)

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.