Haemoperitoneum associated with bilateral granulosa cell tumours in a pregnant mare treated by standing ovariectomy.

Summary: This report describes the likely development and growth of bilateral granulosa cell tumours (GCTs) in a Warmblood pony mare, during the first trimester of pregnancy after artificial insemination. The GCTs were initially suspected to be ovarian haematomas and were managed conservatively. However, they ultimately led to life‐threatening haemoperitoneum (HP) and were later diagnosed as GCTs with histopathology. The case was successfully managed with emergency standing laparoscopic‐assisted bilateral ovariectomy after haemodynamic supportive therapy. The mare made a full recovery and delivered a live filly foal at term. GCTs can be a rare cause of life‐threatening HP and can be successfully managed with haemodynamic support and standing laparoscopic‐assisted removal. Bilateral ovariectomy in a pregnant mare after 70 days of gestation can result in successful delivery of a live foal. [ABSTRACT FROM AUTHOR]