Rare Monkey Saved From Amputation at Chester Zoo Gives Birth Months Later

A critically endangered roloway monkey has given birth just months after a pioneering operation spared her from having her foot amputated. Masaya, a 15-year-old roloway monkey at Chester Zoo, underwent complex surgery last summer after developing a golf-ball-sized mass on her foot. Zoo veterinarians worked with surgeons from the University of Liverpool's Small Animal Teaching Hospital to remove the mass while preserving as much of the foot as possible; the team could find no previous examples of the same procedure being performed on a roloway monkey. The operation succeeded, letting Masaya keep all but one of her toes.

Masaya has since given birth to a daughter named Lagertha, her third. "This was the last chance to save Masaya's foot before amputation," said Rachel Burrow, a University of Liverpool veterinarian and lecturer who helped with the CT (computed tomography) scan and the operation. "Working with primates is completely different from my usual patients, who are typically cats and dogs, and it was a real privilege to care for such a rare animal. It's great to see the surgery was a success — she's comfortable, active, and using the limb well."

Zoe Edwards, a primate keeper at Chester Zoo, said the success of the operation became even more important after the birth, since Masaya's ability to use her foot normally could play a crucial role in caring for her offspring. "Masaya is a very experienced mum and she's parenting magnificently," Edwards said. "If she'd had an amputation, we'd have been left with real questions about whether she could hold her offspring or continue with her normal behaviors." Chester Zoo is one of only two places in the UK where roloway monkeys can be found, and Masaya is part of the European Endangered Species Programme, a coordinated breeding effort; according to the International Union for Conservation of Nature, fewer than 2,000 roloway monkeys remain in the wild, in Ghana and Ivory Coast, threatened by habitat destruction and poaching.

Masaya's foot problems had troubled her repeatedly since she arrived at Chester Zoo in 2023. X-rays, ultrasounds and biopsies failed to pin down the cause, which vets eventually suspected was a persistent abscess, possibly from an old thorn injury. When the swelling worsened in 2025, the zoo transported Masaya to Liverpool for a CT scan. "It's not every day you take a monkey to vet school," said Charlotte Bentley, a veterinary officer at the zoo's Animal Health Centre. "Following the scan, we decided an operation was the way forward. She's been an absolute trooper all the way through."