The Japanese government disposed of “dangerous animals” (not only carnivores but also herbivores, such as elephants) in zoos and circuses during WWII, including those in Japan and occupied Korea, Taiwan, and Manchuria. While some European zoos also destroyed their animals, no country conducted as nationwide and systematic a disposal of captive animals as Japan. Some claim the Japanese government ordered the killings to mobilize the whole civilian population into total war, rather than for the ostensible purpose of public safety.
Here is an excerpt from my book Enemy in the Mirror:Love and Fury in the Pacific War:
In the morning, during a brief stop at Kobe, they heard the terrible news. Hundreds of B-29s had rained incendiary bombs on Tokyo during the night. Forty square kilometers of the city had been set afire and more than 90,000 people were dead. It was beyond imagination. Everyone sat in numbed silence as the train moved on. After staring blankly out the window for many kilometers, Isamu finally closed his eyes and drifted into reverie.
It was a warm Sunday afternoon in 1932 at Tokyo’s Ueno Zoo. Lighthearted families strolled between the enclosures of exotic animals. Rising Sun flags fluttered over the promenade and the cherry trees were in full bloom. A banner proclaimed: “Enrich the country, strengthen the Army.” Like a caring older brother, Japan was bringing light to Manchuria. Soon all of Asia would be joined in a sphere of co-prosperity. Isamu beamed at his parents when they bought him a delicious brown sugar rice and millet cake. He loved all the animals, but his favorite was Tonki, the performing elephant. Tonki carried logs, walked along wooden beams and blew a toy trumpet with his trunk. As a finale, he stood on a podium and raised his trunk and a front leg saluting the crowd. The children cheered and the adults applauded.
Isamu opened his eyes. Tonki and the other zoo animals were long gone – starved to death by their keepers in 1943 for fear they might run wild in an air raid. Now the great city itself was burned to the ground. He rubbed his forehead and ran his fingertips through his hair. How much longer can this go on?