Houston Zoo mourns the death of Nimue, one of the zoo's female lions

HOUSTON, Texas (KTRK) -- The Houston Zoo announced Saturday, July 10, that Nimue, a female lion who had been at the zoo for over 12 years, has passed away.

"Despite emergency intervention by the Zoo's veterinary team, her condition was too severe, and the team made the difficult decision to humanely euthanize the 12-year-old big cat," officials stated in a news release.

Nimue had surgery on July 1 to remove bone fragments stuck in her gastrointestinal tract. She showed signs of a healthy recovery, but animal care professionals found the big cat unexpectedly unresponsive on Saturday.

"Our team of keepers who have spent more than a decade caring and bonding with this incredible animal is grieving this loss, and we support them through this sad time," said Lisa Avendano, the zoo's Vice President of Animal Programs.

Nimue, her surviving pride, and male lion Hasani are ambassadors for their wild counterparts in Africa and serve to educate guests about the work being done to help save this vulnerable species, the zoo notes.