Endangered roloway monkey gives birth after limb-saving surgery: full analysis

A limb-sparing surgery on a critically endangered roloway monkey at Chester Zoo has now been followed by a successful birth, turning what began as a difficult orthopedic and soft-tissue case into a broader conservation milestone. Masaya, a 15-year-old female, gave birth to an infant named Lagertha months after veterinarians at Chester Zoo and surgeons from the University of Liverpool’s Small Animal Teaching Hospital removed a large mass from her foot and preserved the limb. (itv.com)

The case began after Masaya developed recurring foot problems following her arrival at Chester Zoo in 2023. According to Chester Zoo’s account cited by ITV News, clinicians suspected the abscess-like lesion may have stemmed from an old thorn injury. When the swelling worsened in 2025, she was referred for CT imaging at Liverpool’s Small Animal Teaching Hospital, which has advanced referral imaging and surgical facilities more commonly used for companion animals but also supports unusual and exotic cases. (itv.com)

Surgeons reportedly found no prior examples of the same procedure being performed in a roloway monkey, so the team adapted existing surgical techniques to the species. The operation removed a golf ball-sized mass and saved all but one of Masaya’s toes. Postoperatively, Chester Zoo says she recovered well, remained comfortable and active, and regained functional use of the limb. That recovery appears to have mattered not only from a welfare standpoint, but also from a maternal one: zoo staff explicitly said a full amputation would have raised real questions about whether she could hold an infant and continue normal behaviors. (itv.com)

The conservation backdrop makes the outcome more significant. Roloway monkeys are listed as Critically Endangered by the IUCN, and Chester Zoo describes habitat loss and poaching as the main threats. IUCN-linked conservation materials have estimated fewer than 2,000 surviving individuals, while some primate conservation groups have suggested the number remaining in the wild could be even lower. Chester Zoo is one of only two collections in the UK holding the species, and the species is managed within an EAZA Ex situ Programme, underscoring how clinically important each breeding female can be. (chesterzoo.org)

Public comments from the care team were measured but telling. Chester Zoo primate keeper Zoe Edwards said Masaya is “parenting magnificently,” and noted that Lagertha, only a few weeks old, is already showing curiosity. Charlotte Bentley, veterinary officer at Chester Zoo, said surgery was chosen after the scan and described Masaya as “an absolute trooper.” Rachel Burrow, a veterinarian and lecturer at the University of Liverpool, said working with primates was very different from her usual cat and dog caseload, and that it was encouraging to see Masaya comfortable and using the limb well after surgery. (itv.com)

Why it matters: For veterinary teams, this is a strong example of conservation medicine in practice, where the clinical goal is broader than simply resolving a lesion. In zoo and wildlife settings, preserving function can have downstream effects on social behavior, maternal care, breeding viability, and the long-term value of an individual within a managed population. The case also highlights the role referral hospitals can play for zoological collections: advanced imaging, specialist surgery, and collaborative planning can expand treatment options even when published precedents are sparse. That may resonate well beyond primate medicine, especially for clinicians managing rare species where evidence is limited and every intervention has population-level implications. (itv.com)

There’s also a husbandry angle. Recent published work on zoo-housed guenons has pointed to reproductive challenges across managed populations, making every successful birth notable in small ex situ groups. In that context, Masaya’s case is not just a feel-good surgical success; it suggests that preserving mobility and normal maternal function can be central to breeding outcomes in fragile populations. That’s an inference rather than a stated conclusion from the zoo, but it is consistent with both the care team’s comments and the broader reproductive constraints reported for guenons in European collections. (itv.com)

What to watch: The next step to watch is whether the teams publish a case report, conference abstract, or technical summary with more detail on imaging findings, surgical approach, anesthesia, rehabilitation, and long-term function. For zoo veterinarians, that kind of documentation would be the most useful legacy of the case, especially because the team said they could not identify a prior roloway-specific example before operating. (itv.com)