Reproductive Complication in Rhesus Macaques (Macaca mulatta): Prevalence, Risk Factors, and Successful Surgical...

Pelvic organ prolapse (POP), including vaginal prolapse, is a prevalent reproductive condition in human and veterinary medicine, yet spontaneous cases are underreported in rhesus macaques (Macaca mulatta). This case study describes the clinical progression and successful surgical intervention of severe, recurrent vaginal prolapse in 2 pregnant, multiparous rhesus macaques at the Tulane National Biomedical Research Center (TNBRC). Over a multiweek period, one of the females experienced multiple prolapse episodes, including postpartum recurrence and failure of conservative management (manual reduction, suture retention techniques, and supportive care). The other female experienced multiple episodes during late gestation that continued despite conservative management. Definitive treatment was achieved through a novel abdominal approach involving uterine and cervical fixation to the rectus abdominis fascia, which resulted in anatomic correction and postoperative stability. A retrospective review of TNBRC records from 2005 to 2024 revealed 21 cases of vaginal prolapse with varied outcomes ranging from spontaneous resolution to euthanasia. Over this 20-year period, the prevalence was 4.71 per 1,000 females, with the most severe cases occurring in obese, multiparous individuals. This report demonstrates a practical and effective surgical alternative for managing severe or recurrent prolapse in rhesus macaques, particularly in reproductive-aged females where preservation of fertility and welfare is prioritized. The findings support the need for a species-specific prolapse grading system and highlight key risk factors such as parity, gestational age, infant size, and pelvic tissue integrity. These cases underline the importance of early detection, comprehensive supportive care, and individualized surgical planning in nonhuman primates, while providing a translational model for POP in women.