How to Assess and Stabilize a Mare Suspected of Periparturient Hemorrhage in the Field

The peripartum period is defined as the time period just before, during, or immediately after parturition. Although the vast majority of foalings proceed without complications, there are certain disease processes that are more common and unique to the peripartum period. One such concern is periparturient hemorrhage (PPH). Important causes of hemorrhage in peripartum mares include arterial rupture, uterine rupture, vaginal varicose veins, cervical lacerations, and other forms of perineal trauma. PPH is a fairly broad term, but for the purpose of this paper, it will be selectively used to refer to the process whereby rupture occurs to one or more of the arterial vessels supplying blood to the uterus and related structures. A serious and often life-threatening condition, PPH is thought to be one of the most common causes of deaths in peripartum mares. A review of 98 records from central Kentucky during the 1992 and 1993 foaling seasons revealed that reproductive complications accounted for the majority (57 of 98 cases) of deaths in peripartum mares. Of the 57 mares that experienced reproductive complications and subsequently died, rupture of a uterine artery was determined to be the cause of death in 40 of these mares. A more recent report provided concurrent evidence regarding uterine artery hemorrhage being the most common post-partum complication in mares. Rupture of the external iliac artery, utero-ovarian artery, and uterine artery have all been attributed to the onset of PPH. Both the external iliac artery and utero-ovarian artery branch directly off of the aorta and the uterine artery branches off of the external iliac artery. Regardless of the site of rupture, PPH can lead to rapid and profound blood loss, which can result in hypovolemic shock and death. Consequently, suspected cases of PPH should be considered as true emergencies that require a timely evaluation and case assessment. The objective of this report is to provide practitioners with a brief overview of PPH and offer recommendations regarding the diagnosis, stabilization, and management of mares with PPH in the field.