Fetal Congenital Diaphragmatic Hernia and Hydramnios in a Quarter Horse Mare.

Hydramnios is an excessive accumulation of fluid within the amniotic compartment. It is a rare condition in mares, often associated with fetal anomalies. Hydrops of fetal membranes predisposes to the rupture of the prepubic tendon, and many authors suggest the induction of parturition to preserve mare's reproductive career. This report presents the case of a 15-year-old multiparous Quarter Horse mare, referred at 268 days of gestation for suspected hydrops. Repeated ultrasonographic exams confirmed an increase in the depth of the amniotic fluid and reduced fetal viability. During the hospitalization, the mare developed a partial rupture of the prepubic tendon. In this case, a conservative approach was elected, and the mare was treated with nonsteroidal anti-inflammatory drugs (NSAIDs) and an abdominal support bandage. At 327 days of gestation, the mare gave birth to a foal with APGAR score 1. The resuscitation attempt was unsuccessful, and the foal died immediately. A post-mortem examination diagnosed a congenital diaphragmatic hernia (CDH) with pleuroperitoneal diaphragmatic eventration.