A Sotheby's employee holds a rare 52.82-carat white diamond ring at Sotheby's auction house on April 12, 2010 in London, England. Price: 7 million USD. (Photo by Dan Kitwood/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.

A student of the Orchestra of Recycled Instruments of Cateura holds an instrument made from recycled material by craftsman Nicolas Gomez, in Cateura, near Asuncion, May 9, 2013. The orchestra is the brainchild of its conductor Favio Chavez, who wanted to help the children of garbage pickers at the local landfill, and the instruments are made from salvaged materials by craftsman Gomez. The orchestra now involves 30 schoolchildren who have toured countries in Latin America, North America and Europe to play music ranging from Beethoven and Mozart to the Beatles and Paraguayan folk songs. (Photo by Jorge Adorno/Reuters)

A Chinese future bride has her friends playing with her dress during a pre-wedding photoshoot in front of the Eiffel tower in Paris, France, August 28, 2015. As young Chinese become wealthier, they take abroad the tradition of taking their wedding photos days before they are married, rather than on their wedding day. (Photo by Philippe Wojazer/Reuters)

Tanzania, 1964. A touching moment between primatologist and National Geographic grantee Jane Goodall and young chimpanzee Flint at Tanzania's Gombe Stream Reserve. (Photo by Hugo van Lawick via National Geographic)

“Stephen John Fry (born 24 August 1957) is an English actor, screenwriter, author, playwright, journalist, poet, comedian, television presenter and film director, and a director of Norwich City Football Club. He first came to attention in the 1981 Cambridge Footlights Revue presentation “The Cellar Tapes”, which also included Hugh Laurie, Emma Thompson and Tony Slattery. With Hugh Laurie, as the comedy double act Fry and Laurie, he co-wrote and co-starred in A Bit of Fry & Laurie, and the duo also played the title roles in Jeeves and Wooster”. – Wikipedia

Photo: English comic Stephen Fry hosts the comedy revue “Hysteria 3” in support of the Terrence Higgins Trust, 1991. (Photo by Dave Hogan/Hulton Archive/Getty Images)

Transgender Kendra Ferrari, 21, performs during Miss Night Queen beauty contest in Guatemala City, Friday, June 15, 2012. Ferrari won the pageant and will represent the transgender community for one year. (Photo by Rodrigo Abd/AP Photo)

“Sperm whale opening it's huge mouth, Ogasawara Islands, Japan. Sperm whales are the biggest carnivorous animals on the planet. Each teeth in the mouth of adult specimen weights more than 1 kilogram. Interestingly enough that modern marine biologists believe that these teeth despite being fearsome play little role in capturing and eating giant squid – with their main function being mainly ritual aggression between males!”. (Photo by Alexander Safonov)