Management of dystocia and fetotomy in a miniature horse mare

Abstract

A five year old miniature horse mare was presented for signs of colic lasting 3 hours. No breeding date was known and pregnancy was not confirmed, but owners suspected late term pregnancy. Physical examination was unremarkable other than elevated pulse (88 bpm) and a full udder. Transabdominal ultrasonography revealed a fetus with no heartbeat and minimal placental fluids. No fetal movement was elicited on transrectal palpation. On transvaginal palpation, the cervix was open, but no fetal extremities were palpable. The mare was determined to have a dystocia and the fetus was presumed deceased. The mare was anesthetized to better assess fetal position. Fetal position was cranial longitudinal, dorsal sacral, with bilateral shoulder and ventral neck flexion. Due to position of the foal, prolonged dystocia leading to death of the foal, and small size of the mare, fetotomy was chosen. When the fetus is dead, fetotomy is often preferred over cesarean section because the mare’s recovery is shorter with less after care.1 Two different studies showed a mare survival rate of 95.8% after fetotomy 2 compared to 85% after cesarean section.3 A single cut was made at the base of the fetal neck using a fetotome, and the head and neck were detached. The head and neck slipped cranially, so the bilateral shoulder flexion was corrected and the body was removed from the uterus utilizing chains on the front limbs. The head and neck were then removed. The uterus was examined and lavaged with isotonic distilled water. No lacerations or rupture were identified. The placenta was retained for 12 hours and standard treatment was initiated. The placenta was passed uneventfully and the mare was discharged after 3 days. This case demonstrates a mare that presented for colic but was experiencing a dystocia. It also indicates when a fetotomy is chosen over cesarean section.