A London-based animal protection organization is lashing out at a Danish zoo for having killed a year-old female lion to avoid inbreeding.

Joanna Swabe, head of the Humane Society International/Europe, says "zoos routinely over-breed" and kill (...) thousands of other animals deemed surplus to requirements."

Swabe says zoos have "an ethical responsibility" and can use contraceptive options "to manage reproduction, prevent inbreeding (and) maintain genetically healthy populations."

There was no immediate reaction from Odense Zoo in central Denmark, where the female lion will be dissected publicly Thursday during the annual school fall holiday. The feline has been kept in a freezer after it was killed nine months ago.

In February 2014, Copenhagen Zoo faced international protests after a giraffe was killed, dissected and fed to lions in front of children.