Dogs and their owners dressed in Halloween costumes parade during the annual Haute Dog Howl'oween event in Long Beach, California on October 30, 2016. The parade, which claims to be the largest Halloween dog event in the world, sees hundreds of dogs and their owners dressed in colorful costumes celebrating the festival. (Photo by Mark Ralston/AFP Photo)

In this picture taken on Sunday, March 5, 2017, a Tehran's urban animal control worker catches a stray dog after being shot with his anesthetic dart on the outskirts of the capital Tehran, Iran. The shelter has been hired by the Tehran city government to take a new, more humane approach to deal with the burgeoning problem of stray dogs in the capital. It’s a sign of changing attitudes among officials in a country where Islamic authorities long saw dogs as “un-Islamic” and would at times confiscate them from people who kept them as pets. (Photo by Vahid Salemi/AP Photo)

German photographer Tanja Brandt has created a series which captures the absolutely heart-breaking friendship between Ingo, her two-year-old German Shepherd, and a tiny owl called Napoleon. "Ingo is not always the calmest dog, however when he is around the birds, and particularly Napoleon, he is very soft and gentle", said the photographer. "He seems very at peace with them".

A dog jumps into water during the “World Dog Show” in Leipzig, Germany, November 10, 2017. Around 31,000 animals are expected at the international pedigree dog competition taking place from 8 to 12 November 2017. (Photo by Hannibal Hanschke/Reuters)

This adorable gallery reveals the astonished expressions of dozens of puppies as they try to gobble up treats flying through the air toward them. Photographer Christian Vieler, 48, has been documenting pooches, with their eyes bulging, mouths wide open and looks of love on their faces, in his studio as part of the project “Dogs Catching Treats” since 2013. (Photo by Christian Vieler/Caters News Agency)

Grand Champion Oakhurst Crusin' in Chrome, an Australian Shepard, poses backstage at the Westminster Kennel Club Dog Show after winning best of opposite s*x on February 13, 2012 in New York City. (Photo by Michael Nagle/Getty Images)

Two De Brazza's monkeys stand together at Port Lympne Wild Animal Park on June 21, 2011 in Hythe, England. Port Lympne has welcomed a host of new arrivals this year with wildebeest, colobus monkeys, gorillas and rhinos all adding to the current stock. Port Lympne and Howletts Wild Animal parks were set up by the late John Aspinall to protect and breed rare and endangered species and, where possible, return them to safe areas in the wild. The Aspinall Foundation which runs the parks also manages two gorilla rescue and rehabilitation projects in the central African countries of Gabon and Congo where they have successfully reintroduced over 50 gorillas to the wild. (Photo by Dan Kitwood/Getty Images)

A 13-month-old chimp named Fumo carries a “Christmas present” of food treats in wrapping paper under his arm during a Christmas-themed feeding time at Sydney's Taronga Park Zoo, December 9, 2014. Fumo, meaning “chief” or “spear” in Swahili, is one of the latest additions to the zoo's successful primate breeding program. (Photo by Jason Reed/Reuters)