Management of retained fetal membranes by umbilical vessel infusion in mares submitted to elective C-section.

Abstract: The cesarian section (C-section) is a potential risk factor for retained fetal membranes (RFM) in mares, requiring prompt diagnosis and treatment to enhance outcomes. This study aimed to evaluate the use of umbilical vessel infusion for the treatment of RFM after elective C-section in mares. Ten pregnant criollo type-mares at 315 days of gestation were monitored daily and underwent elective C-section upon readiness for birth. All mares exhibited RFM, with placentas retained beyond three hours careful extraction of the foal by C-section. Those were randomly assigned into two groups: Umbilical vessel infusion (n = 5): using of low-pressure 0.9 % saline solution infusion into the umbilical vessel; or Counterweight (n = 5): involving a light counterweight (1 kg) attached to the exposed fetal membrane. Mares that presented time from onset treatment to full separation and expulsion of the fetal membrane by 40 min were classified as responsive to treatment. There were no differences in mares' age (8 ± 2, 3-20 years), gestational length (333 ± 3, 328-360 d), foal weight (38 ± 2, 30-50 Kg), the surgical time to C-section (124 ± 5, 90-150 min), and time of uterine manipulation during C-section (57 ± 3, 45-70 min) between groups. Results showed that 80 % (n = 4/5) of mares in the Umbilical Vessel Infusion group achieved membrane expulsion within 40 minutes, while none (0 %, n = 0/5) in the Counterweight group responded within this timeframe (P < 0.05). Mares receiving the umbilical vessel infusion method have not experienced severe signs of discomfort, pain, or additional secondary side effects after the procedure. In conclusion, umbilical vessel infusion is an effective, safe, and practical method for the treatment of retained fetal membranes after C-section in mares.