A member of “Laughter Doctors of Ciudad Juarez” performs at a children's hospital in Ciudad Juarez March 11, 2015. Through clown performances, music and interactive activities, the group of doctors visit different hospitals throughout the border city, using laughter to help aid the recovery of young and elderly patients suffering from serious illness or injury, as well as provide hope for the hospitalized patients and their families, local media reported. (Photo by Jose Luis Gonzalez/Reuters)

In this May 8, 2015 photo, sisters Zoraida Infante, left, and Graciela Trujillo pray on Fishermen's Beach before therapeutic swimming in the Pacific Ocean in Lima, Peru. Under overcast skies, the bathers practice thalassotherapy, which derives from the Greek “thalasso”, for “sea”, and draws on the ocean's healing properties. (Photo by Rodrigo Abd/AP Photo)

A Palestinian social activist working for the International South South Cooperation (Cooperazione Internazionale Sud Sud, or CISS) entertain children who are patients inside a hospital in Gaza City August 31, 2015. Activists working for the Italian non-profit NGO use entertainment and humour to help bring treatment to children suffering from psychological trauma in the Gaza Strip. (Photo by Mohammed Salem/Reuters)

In this Thursday, March 17, 2016 photo, 33-year-old Palestinian clown doctor Alaa Miqdad, left, entertains 3-year-old patient Yaqin Shawaf, who suffers from dialysis, in the department of kidney diseases at Al-Rantisi children's hospital in Gaza City. (Photo by Adel Hana/AP Photo)

A woman reacts after performing Otonamaki, which translates as “adult wrapping”, a new form of therapy where people are wrapped in large swaddling cloth to alleviate posture problems and stiffness, at a session in Asaka, Saitama prefecture, Japan, February 4, 2017. (Photo by Toru Hanai/Reuters)

Old Heidelberg, Dog with Pipe, 1905. (Photo by Detroit Publishing Company)

A mascot of the Philippine National Police (PNP), named after their Chief Director General Ronald Dela Rosa, marches with members of the K9 units and the Special Action Force before the mass blessing for rescue dogs during the celebration of the feast day of St. Francis of Assisi, patron Saint of Animals, at the St. John Paul II parish church in Eastwood, Quezon city, metro Manila, Philippines October 2, 2016. (Photo by Romeo Ranoco/Reuters)

A dramatic rise in owning exotic pets in China is fuelling global demand for threatened species. The growing trade in alligators, snakes, monkeys, crocodiles and spiders is directly linked to species loss in some of the world’s most threatened ecosystems. Here: A fennec fox (Vulpes zerda) is groomed in a pet store in central Beijing. Native to the Sahara in North Africa, the species became a popular pet after being depicted as a character in Disney’s 2016 animated movie Zootopia. Individuals can cost between $2,000–$3,000. (Photo by Sean Gallagher/The Guardian)