Theriogenology question of the month. Peritonitis secondary to a vaginal laceration during natural breeding in a mare.

The research focuses on the case of a mare who developed peritonitis due to a vaginal laceration that occurred after natural breeding, requiring intensive veterinary examination and intervention.

Background and Initial Symptoms

• The subject of the study was a 12-year-old American Paint mare who was brought to a veterinary hospital. The mare presented symptoms of discomfort similar to colic after being naturally bred three times over a 72-hour period.
• Abnormalities were initially detected when blood was observed on the stallion’s penis after the final round of mating. Post-breeding, the mare showed colic-like behavior, the posture pointing towards a need to urinate, and passing of a vulvar discharge that contained blood.

Primary Examination and Medication

• On observing the continued discomfort in the mare two hours after the final breeding, it was administered two medications – flunixin meglumine and xylazine hydrochloride. Despite the drugs, the mare’s discomfort persisted leading to a referral to the University of Florida for a thorough examination.
• Upon admission, a complete physical examination was undertaken. Samples were collected for numerous tests including a complete blood count, serum biochemical analysis, blood gas analysis, and measurements of Packed Cell Volume (PCV) and total protein concentration. This examination revealed the mare’s increased heart rate and signs of recent bloody vulvar discharge.

Further Investigation and Diagnosis

• A resultant reproductive examination revealed a large laceration in the wall of the mare’s vagina. A digital manual examination confirmed that the vaginal wall was fully perforated, although the cervix was intact and had no signs of trauma.
• A transabdominal ultrasonography yielded no abnormal findings but detected a normal amount of fluid in the abdomen. This fluid was collected and sent for further analysis and examination.

Lab Test Results

• Lab test analysis showed neutrophilia, indicating an increased number of neutrophils which are a type of white blood cell, indicating a possible infection. The mare also had an increased concentration of fibrinogen, a blood protein that contributes to clotting, indicating an inflammation or response to tissue damage.
• Further analysis showed increase in white blood cells in the abdominal fluid sample, supporting an inflammation hypothesis. However, no bacteria were identified. A lack of an adequate sample volume prevented analysis of total protein concentration in the abdominal fluid.