A second lynx, belonging to a zoo where one escaped and was later shot, has died following a “handling error”.
In a statement, the zoo confirmed an investigation was under way after the death of the second lynx, Nilly.
The Lynx UK Trust called for the zoo to be closed, saying the deaths were “unacceptable”.
Ceredigion council said it was investigating this second death.
Owner Tracey Tweedy said staff had given Nilly mouth to mouth after she became twisted in a catch-pole as staff tried to move her into a different enclosure ahead of a council inspection.
She said she also rubbed her heart and added staff were horrified by the deaths.
“I don’t regret buying this place because I know that despite all this we will make it what it should be,” she said.
“It is a sanctuary for animals and they should be here and be safe and the fact that we have let down two of our precious lynx is just horrific. There is no excuse.”
Paul O’Donoghue, a scientific adviser at the Lynx UK Trust, which is trying to reintroduce them in the UK, said he had visited the zoo at the weekend.
“To have two die, it’s unacceptable on every level. Serious questions need to be asked about the husbandry at this zoo,” he said.
The trust has started a petition calling for the zoo’s closure which has been signed by more than 1,400 people.
The zoo’s owners said they had been “working hard to make vast improvements” over the summer and plans were in place to build a new lynx enclosure.
Ceredigion council said the death of Nilly was brought to its attention “the day after the animal had been inadvertently killed”.
The council spokesman added: “Due to an ongoing investigation, we are unable to provide further comment.”
The council said despite “exhaustive efforts” to recapture her, it was necessary to act because she had strayed into a populated area and “the safety of the public was paramount”.
Lilleth is believed to have escaped after making a “giant leap” over an electrified fence.
Among those to criticise the council’s decision to shoot Lilleth was TV presenter Ben Fogle who tweeted that “dogs cause more injury to sheep and people”.
The Farmers’ Union of Wales said the killing “was long overdue” given the danger to people and livestock.
Dean and Tracy Tweedy took over Borth Wild Animal Kingdom less than six months ago.
They said the zoo would remain closed until further notice.