Argentine authorities in 2020 shut down the Luján Zoo — famous for letting visitors handle and pose for pictures with tigers and lions — over mounting safety concerns.

But on Thursday, lions, tigers and bears that managed to survive in substandard conditions at the now-closed zoo on the outskirts of Buenos Aires, are still pacing weakly their claustrophobic cages.

They are waiting to receive urgent veterinary care for the first time in years.

The 62 big cats and two brown bears were being evaluated and treated before their eventual transfer to vast wildlife sanctuaries abroad.

But the plight of the captive cats there only worsened. For the past five years, the animals were sustained by little more than a few loyal zookeepers who, despite having lost their jobs at Luján, took it upon themselves to feed and care for the animals at the deserted zoo.

Most didn’t make it.

When Four Paws, an international animal welfare organization, first visited the zoo in 2023, caretakers counted 112 lions and tigers — already down from the more than 200 big cats believed to have been housed in the zoo at the time it was closed.

Two years on, almost half of the animals have succumbed to illnesses from poor nutrition, wounds from fights with animals they’d never encounter in the wild, infections from lack of medical attention and organ failure from the stress of living in such cramped conditions.

Four Paws' chief program officer, Luciana D’Abramo, said it was shocking, pointing to a 3-meter by 3-meter cage crammed with seven female lions.

Next-door, two Asian tigers shared a tiny cage with two African lions.

At sanctuaries run by Four Paws around the world, a single lion typically gets 10,000 square meters to itself.

After striking an agreement with Argentina’s government earlier this year, Four Paws took over responsibility for the surviving wild animals in Lujan last month.

The memorandum of understanding involved Argentina committing to end the sale and private ownership of exotic felines in the large South American country, where enforcement efforts often run aground across 23 provinces that have their own rules and regulations.

The Vienna-based organization has previously evacuated starving tigers from Syria's civil war, abandoned bears and hyenas from the war-ravaged Iraqi city of Mosul and freezing lion cubs from the besieged Gaza Strip, but it has never rescued such a large number of big cats before.

Dr. Amir Khalil, the veterinarian leading the group’s emergency mission called it "one of our biggest missions ... not only in Argentina or Latin America, but worldwide."

On Thursday, vets and experts from the organization were scrambling around the derelict zoo to assess the animals one by one. Most had not been vaccinated, sterilized or micro-chipped for identification.

The team whisked sedated lions and tigers onto an operating table, dispensing nutrients, antibiotics and doses of pain medication via IV drips.

The quick check-ups frequently transformed into emergency surgeries. One tiger was treated for a bleeding gash in its tail last week, another for a vaginal tumor on Thursday. Several tigers and lions needed root canals to repair infected molars that had been broken on the steel cage bars.

Others received treatment for claws that had grown inward from walking too much on unnatural, plank flooring in the spartan enclosures.

After evaluating each animal over the course of the coming weeks, Four Paws will arrange for their transfer to more expansive, natural homes around the world.

Some Argentine zookeepers who spent decades feeding and caring for the big cats say they're happy to see Four Paws improving the conditions. But there was also a sense of nostalgia for how things were.

AP Video by Victor R. Caivano