Hemorrhagic Vulvar Discharge Caused by Vestibule Trauma in a Nonpregnant Thoroughbred Mare

•Describes a unique cause of frank hemorrhagic vulvar discharge in mares.•Discusses differential causes of bloody vulvar discharge in mares.•Highlights the importance of a thorough physical examination and history evaluation to attain diagnosis.

A 12-year-old Thoroughbred mare presented with a history of frank, acute, hemorrhagic vulvar discharge. The mare had delivered five healthy foals before being donated to the university and was currently not pregnant. The mare was housed with a small group of Thoroughbred and Quarter Horse mares, and while being moved to another pasture, the subject mare was witnessed by caretakers and one of the authors to be attacked (bitten) by a herd mate in the perineal region. Hemorrhagic vulvar discharge was noted immediately thereafter. The mare was sedated, and the urogenital tract was thoroughly examined via vaginal palpation and speculum as well as transrectal ultrasonography. A defect involving the mucosa and submucosa of the vestibule was identified as the source of the hemorrhage. The wound was cleaned and sutured to speed up the healing process. The mare was treated with flunixin meglumine for 2 days and antibiotics for the next 5 days and was completely recovered 2 weeks after the incident. Several causes have been identified in association with hemorrhagic vulvar discharge. In the present case, the cause was easily identified as being trauma-induced due to the fact that incident had been witnessed to have occurred. In other instances where this is not the case, a systematic approach to diagnosing the source of blood must be implemented.