A dog trainer works with a previously abandoned dog at a police centre in Saltillo, Mexico March 4, 2016. Stray dogs are adopted by the police from a municipal anti-rabies centre and then trained to help the police patrol the streets, and search for drugs, explosives and weapons. (Photo by Daniel Becerril/Reuters)

A musher handler with Alan Eischens team embraces one of Eischen's dogs just before the ceremonial start of the Iditarod Trail Sled Dog Race that begins a near 1,000-mile (1,600-km) journey through Alaska’s frigid wilderness in downtown Anchorage, Alaska March 5, 2016. (Photo by Nathaniel Wilder/Reuters)

A U.S. Army soldier with the 10th Special Forces Group and his military working dog jump off the ramp of a CH-47 Chinook helicopter from the 160th Special Operations Aviation Regiment during water training over the Gulf of Mexico as part of exercise Emerald Warrior 2011 on March 1, 2011. (Photo by Tech. Sgt. Manuel J. Martinez/U.S. Air Force)

Dogs, Pretty, Llilly, and Rocky wait for their turn to be examined by veterinarians during a community campaign for the sterilisation and deworming of dogs and cats in Havana, Cuba February 25, 2016. (Photo by Reuters/Stringer)

Flash, a golden retriever, plays with a toy following a press event for the American Kennel Club to reveal the nations most popular dog breeds in the Manhattan borough of New York, February 22, 2016. (Photo by Carlo Allegri/Reuters)

Siberian Huskies pull a contestant during the “Kara-Dag 2016” open amateur dog sled and skijoring race near the village of Yelovoye in Taiga district, outside Krasnoyarsk, Siberia, Russia, February 21, 2016. Dogs and their owners from various regions of Siberia took part in an annual race. (Photo by Ilya Naymushin/Reuters)

A dog named Rama surfs a wave off Sydney's Palm Beach with its owner, Australian dog trainer and former surfing champion Chris de Aboitiz (not pictured), February 18, 2016. An Australian dog trainer and former surfing champion is using the discipline of surfing as a way of teaching owners to build healthy relationships with man's best friend. (Photo by Jason Reed/Reuters)

French bulldog Watson is wheeled to a ring for judging at the 2016 Westminster Kennel Club Dog Show in the Manhattan borough of New York City, February 15, 2016. (Photo by Mike Segar/Reuters)