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

Area of Science:

• Reproductive biology
• Primate medicine
• Surgical innovation

Background:

• Pelvic organ prolapse (POP), including vaginal prolapse, is a common condition in humans and animals.
• Spontaneous cases are underreported in rhesus macaques (Macaca mulatta).
• Severe, recurrent vaginal prolapse poses significant welfare concerns in nonhuman primates.

Purpose of the Study:

• To describe the clinical progression of severe, recurrent vaginal prolapse in pregnant rhesus macaques.
• To report the successful surgical intervention using a novel abdominal approach.
• To provide a translational model for pelvic organ prolapse in women.

Main Methods:

• Case study of 2 pregnant, multiparous rhesus macaques with severe vaginal prolapse.
• Conservative management failure (manual reduction, suture retention, supportive care).
• Novel abdominal surgery: uterine and cervical fixation to rectus abdominis fascia.
• Retrospective review of 21 cases (2005-2024) at TNBRC.

Main Results:

• Conservative management failed in both cases.
• The novel abdominal surgical approach achieved anatomic correction and postoperative stability.
• Retrospective data revealed a prevalence of 4.71 per 1,000 females, with severe cases in obese, multiparous individuals.
• Key risk factors identified: parity, gestational age, infant size, pelvic tissue integrity.

Conclusions:

• A novel abdominal surgical technique is effective for severe or recurrent vaginal prolapse in rhesus macaques.
• This approach prioritizes fertility and welfare in reproductive-aged females.
• Findings support the need for a species-specific prolapse grading system and highlight critical risk factors.