Huellas, a paraplegic dog in a wheelchair, walks at Pescadores beach in Chorrillos, Lima, September 7, 2015. Sara Moran has an animal shelter called Milagros Perrunos where she cares for stray dogs and shelters dogs injured from traffic accidents or domestic abuses. With donations and raffle, Moran purchases wheelchairs, food and medical treatment for the dogs at her shelter. (Photo by Mariana Bazo/Reuters)

Zappa, a toothless 15-year-old Italian greyhound that looks surprisingly like Sid the Sloth from the animated movie Ice Age, is redefining dog beauty. Owners Sadie and Rosalie Millen, of Pewaukee, Wisconsin, say that Zappa started sticking her tongue out a few years ago when she lost her teeth.

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)

Unnati, 6 years old, at home with his sister Ishika, 4 years old, in the Mahamai Ka Bagh neighborhood. Unnati was born to parents contaminated by a carcinogenic and mutagenic water supply. This year marks the 31st anniversary of the 1984 Union Carbide gas tragedy that killed thousands of citizens of Bhopal within 72 hours and has gone on to claim thousands more as a result of the polluted environment. (Photo by Giles Clarke/Getty Images)

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)

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)

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)