Equine Uterine Artery Rupture Study Guide

Overview and Clinical Importance

Uterine artery rupture (periparturient hemorrhage) is a life-threatening emergency that occurs when arteries supplying blood to the equine reproductive tract rupture, typically around the time of foaling. This condition represents one of the most common causes of death in periparturient mares, accounting for up to 40% of postpartum mare fatalities. Understanding the pathophysiology, clinical presentation, and emergency management of this condition is essential for NAVLE success and clinical practice.

The condition predominantly affects older, multiparous mares (greater than or equal to 15 years of age) and can occur before, during, or after parturition. In a 15-year necropsy study of 513 horses with periparturient arterial rupture, 78% were 15 years of age or older. The hemorrhage may be contained within the broad ligament (forming a hematoma) or rupture into the abdominal cavity (hemoabdomen), with the latter carrying a significantly worse prognosis.

Vascular Anatomy of the Equine Uterus

Understanding the blood supply to the mare's uterus is critical for comprehending the pathophysiology of uterine artery rupture. The arterial supply to the equine uterus is unique compared to other domestic species and involves three main vessels: