Igor, the 13 year-old Siberian tiger lies on the operation table before the non-invasive stem cell surgery in Zoo Szeged, Hungary April 18, 2018. (Photo by Bernadett Szabo/Reuters)





An attendant carries a monkey after its sterilization at a monkey rescue center run by forest and wildlife department Tutikandi in the northern Indian hill town of Shimla November 14, 2011. (Photo by Mukesh Gupta/Reuters)





A veterinarian from the Zoological Foundation of El Salvador uses a stethoscope on a female dolphin in San Diego, El Salvador October 25, 2012. (Photo by Ulises Rodriguez/Reuters)





Bo, a 55-day-old baby Echidna known as a puggle, rests in the hands of vet nurse Annabelle Sehlmeier at Taronga Zoo in Sydney November 1, 2012. The puggle was brought to the zoo after it being found by itself on a walking track north of Sydney and will be fed by hand until it is weaned at about six months of age. (Photo by Tim Wimborne/Reuters)





Veterinarians prepare Budapest Zoo's oldest gorilla, Liesel, for an operation to remove fibroid tumours from its uterus in Budapest January 15, 2009. (Photo by Reuters/Pool)





Veterinary physiotherapist Livia Pereira (L) holds the head of paralyzed lion Ariel as a veterinary works on plasma exchange treatment machine in the living room of Pereira's home in Sao Paulo July 20, 2011. Pereira's home has turned into a hospital since the three-year-old lion started a landmark treatment to cure a rare autoimmune disease which paralyzed its legs about a year earlier. (Photo by Nacho Doce/Reuters)





A veterinarian attends to “Puntung”, a newly captured female Sumatran Rhinoceros (Dicerorhinus sumatrensis) in Lahad Datu, in Malaysia's state of Sabah on Borneo island January 12, 2012. (Photo by Angie Teo/Reuters)





A Brazilian vet injects a vaccine in a Boa constrictor at the Sauim Castanheira Wildlife Refuge in Manaus, Brazil July 20, 2012. (Photo by Bruno Kelly/Reuters)





Veterinarian Len Lucero feeds the piglet known across the internet as Chris P. Bacon in his office in Clermont, Florida February 13, 2013. The piglet's hind legs are deformed and Dr. Lucero had fashioned a wheelchair out of K'nex toys to help the piglet walk. (Photo by Scott Audette/Reuters)





Veterinarians prepare a stray dog for sterilization at Dogtown, a protection, care and adoption center for stray animals in Uzunu, Romania April 25, 2013. (Photo by Bogdan Cristel/Reuters)





A veterinarian takes a blood sample from an Andean condor, one of the world's biggest flying birds, at a veterinary hospital in Los Andes, Chile August 12, 2013. (Photo by Ivan Alvarado/Reuters)





Carnivore keeper Andy Wolfenden carries Juba the cheetah cub into the operating theater after being anesthetized ahead of his operation to repair a right ankle fracture at Chester Zoo, northern England February 3, 2012. (Photo by Phil Noble/Reuters)





Veterinarian Miguel Angel Mansilla holds up a green sea turtle after it was treated for injuries at the University at Concepcion, south of Santiago, Chile, April 16, 2014. (Photo by Jose Luis Saavedra/Reuters)





A veterinarian technician Chellan Robinson wades with a false killer whale calf after it was rescued near the shores of Tofino and brought to the Vancouver Aquarium Marine Mammal Rescue center in Vancouver, British Columbia July 11, 2014. (Photo by Ben Nelms/Reuters)





A vet feeds a cub of guina cat (Leopardus guigna) in a rescue center in at Concepcion city, Chile February 1, 2014. The guina cat is known as the America's smallest wildcat and is in danger of extinction. The cub was found abandoned at a wood nearby the city. (Photo by Jose Luis Saavedra/Reuters)





A vet administer glucose to an elephant named Ayyappan after it was rescued from a marshland on the banks of the Vembanad Lake, on the outskirts of the southern Indian city of Kochi February 6, 2014. (Photo by Sivaram V/Reuters)





A zoo staff member touches Mango, a 19-year-old Syrian brown bear, during preparations for his surgery on a slipped disk at the Ramat Gan Safari near Tel Aviv May 7, 2014. (Photo by Nir Elias/Reuters)





Foreign veterinarians and local staff carry out a check-up on a brown bear at the Four Paws Bear Sanctuary in Pristina, Kosovo May 2, 2014. (Photo by Hazir Reka/Reuters)





Veterinarians prepare Tango, an 11-year-old male jaguar, for a full medical examination at the Buenos Aires Zoo October 27, 2014. (Photo by Enrique Marcarian/Reuters)





Thierry Petit, zoo veterinarian, weighs a black-and-white ruffed lemur at the family-owned Palmyre Zoo in the pine forest of Les Mathes, in the Charente Maritime region, western France, November 20, 2013. (Photo by Regis Duvignau/Reuters)