This unique collection of photographs shows the concentrated faces of dogs just before catching their beloved treats. Professional photographer Christian Vieler, from Germany, shot the latest series of his “Dogs Catching Treats in Trouble” collection with hilarious results. Here: Hudson the Rhodesian Ridgeback. (Photo by Christian Vieler/Caters News Agency)

An army dog stands up as retiring soldiers salute their guard post before retirement in Suqian, Jiangsu province, China on November 29, 2017. (Photo by Reuters/China Stringer Network)

A dog is seen at the entrance of a house in the flooded residential area of Villeneuve-Saint-Georges, near Paris, France January 26, 2018. The Paris region has been deeply affected by the floods that hit the country over the past week, but in Paris, it was business as usual. (Photo by Christian Hartmann/Reuters)

View of an American marine as he lies in a foxhole and whistles at a husky, one of the scouting dogs used during the landing on Guam, August 1944. (Photo by W. Eugene Smith/Time & Life Pictures/Getty Images)

Sharon Stone and Anton Rivas by Thierry Le Gouès for French Revue de Modes #20, Spring/Summer 2012 (Dog Day Afternoon; Photo by Thierry Le Gouès; Styling: Marcell Rocha)

A Black and Tan Coonhound named Harbor has the longest ears of any living dog, with measurements of 12.25 (31,12 cm) inches for the left ear and 13.5 (34,29 cm) inches for the right. (Photo by Ryan Schude/Guinness World Records via AP)

A dog wears “The Flash” costume for a carnival pet parade in Rio de Janeiro, Brazil, Sunday, January 31, 2016. People dressed their pets up for the annual block parade held near Copacabana beach. (Photo by Leo Correa/AP Photo)

A girl pours water over a dog to cool it down, in the rebel held besieged town of Douma, eastern Damascus suburb of Ghouta, Syria, June 23, 2016. (Photo by Bassam Khabieh/Reuters)