The procedure was carried out in Vietnam by Edinburgh Zoo vet Romain Pizzi, the only UK vet specialising in zoo and wildlife keyhole surgery.

BBC: Pioneering surgery for moon bear by Edinburgh vet

Some questioned why he wasn't relocated or placed in a zoo rather than being shot by wildlife officers.

CNN: Switzerland's only wild bear is killed as a danger to humans

The Bronx Zoo's Wildlife Conservation Society is a leader, with 270 projects in 51 countries.

ECONOMIST: From zoo cage to modern ark

In fact they don't even call it a zoo, it is a wildlife park, the animals are slightly more free.

BBC: Elephant crushes keeper

But at the Highland Wildlife Park near Aviemore, Britain's only zoo to have polar bears, they are going in the opposite direction.

BBC: Knut: A polar bear story

The zookeeper was a longtime employee at the wildlife park and had worked with the group of wolves since they were born, the zoo said in a statement on its website.

CNN: Zookeeper killed by wolves in Sweden