Three-years-old dog Hope uses a wheelchair to run next to its owner Regine Grosinger in Vienna September 3, 2014. Hope was found with cut-off back legs in the countryside and brought to an animal asylum when it was four-month-old. Grosinger took the dog home two months later and had a wheelchair manufactured for it. (Photo by Heinz-Peter Bader/Reuters)

A 2-year-old Florida panther is released into the wild by the Florida Fish and Wildlife Conservation Commission (FWC) on April 3, 2013 in West Palm Beach, Florida. The panther and its sister had been raised at the White Oak Conservation Center since they were 5 months old. The FWC rescued the two panthers as kittens in September 2011 in northern Collier County after their mother was found dead. The panther is healthy and has grown to a size that should prepare him for life in the wild. (Photo by Joe Raedle)

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)

A boy stands at the door of a 60-year-old cable car in the town of Chiatura, some 220 km (136 miles) northwest of Tbilisi, September 12, 2013. (Photo by David Mdzinarishvili/Reuters)

Mr. Zhong Hua, of Johns Hopkins University School of Medicine, took this image of the peripheral nerves (those outside of the brain) in an 11.5-day-old mouse embryo, magnified five times. (Photo by Zhong Hua)

Mulan Jamilah, a 6-year-old Bengal tiger, kisses caretaker Abdullah Sholeh, 33, in the garden beside their home on January 20, 2014 in Malang, Indonesia.

Svetlana Tseyko feeds a 10-month-old moose named Grisha in the courtyard in the village of Abramy, some 160 km northwest of Minsk, on February 21, 2017. (Photo by Sergei Gapon/AFP Photo)