Washington - Two newborn cheetahs are settling into Washington's National Zoo after they beat the odds and came in the world in circumstances worthy of a veterinary thriller, the zoo said.
Their mother Ally bore one of the cubs, a male, on April 23 at the Smithsonian Conservation Biology Institute outside the US capital and - not unexpectedly for a first-time cheetah mother in captivity - abandoned it.
Keepers then transferred the cub to a veterinary hospital to be treated for severe hypothermia.
But when Ally suddenly stopped having contractions hours later, veterinarians anesthetised her to see if any additional cubs might still be in her womb - and indeed, the heartbeats of three other cubs were detected inside.
Veterinarians led by Copper Aitken-Palmer performed a rare caesarean section, which baby cheetahs typically fail to survive.
But while two of the remaining cubs womb died, one hung on - thanks in part to three hours of CPR resuscitation, medication and frantic efforts to keep the newborns warm.
"That little female is a fighter," Aitken-Palmer said. "Once we got her breathing, she just kept going. It was a very intense, stressful experience, but among the most inspiring of my career."
Both surviving cubs and their mother remained in intensive care for three days. Their father, Caprivi, was brought in to donate plasma to boost their immune systems, before their transfer this week to the National Zoo's Cheetah Conservation Station.
"The cubs are being hand-raised at the Zoo and will require around-the-clock care until they are ready to make their public debut late this summer," the zoo said in a statement.
The Cheetah Conservation Station's curator Tony Barthel said "the cubs will continue to need care and we're not out of the woods yet".
"The goal is to ensure that the cheetahs thrive and become ambassadors for their species," he added.
Cheetahs are the fastest animals on land, but they are struggling to survive in their native African habitat, with only an estimated 7 500 to 10 000 left in the wild, the zoo said.
The International Union for Conservation of Nature considers them a vulnerable species.