Splenic hematoma and hemoperitoneum in a Thoroughbred racehorse after racing

To describe the clinical presentation of a Thoroughbred filly with acute hemoperitoneum from a splenic source immediately after racing.

A 3-year-old Thoroughbred filly used for racing and that had raced shortly before presentation to the hospital.

On presentation, the filly was quiet, alert, and responsive with a heart rate of 76 beats/min, pale mucous membranes, and absent borborygmi. All other physical examination parameters were within normal limits. Abdominal ultrasound was performed and revealed echogenic free abdominal fluid and a splenic hematoma. Abdominocentesis yielded sanguinous fluid with a PCV of 35%. The next day, repeat ultrasound revealed the splenic hematoma with capsular separation.

The filly was treated overnight with isotonic crystalloid fluids and aminocaproic acid (40 mg/kg, IV, slow bolus over 30 minutes followed by 20 mg/kg, IV, q 6 h), potassium penicillin (22,000 IU/kg, IV, q 6 h), gentamicin (6.6 mg/kg, IV, q 24 h), and omeprazole (4 mg/kg, PO, q 24 h). The lowest PCV obtained from the filly was 36 hours after presentation. The filly stabilized with medical treatment and was discharged to a farm for further recuperation.

There are no published reports detailing hemoperitoneum of splenic origin in Thoroughbreds immediately after racing. Hemoperitoneum of splenic origin is not common in horses, with most cases of hemoperitoneum being secondary to acute trauma, neoplasia, parturition, or postoperative complications. While uncommon, this case raises awareness to another differential for a colicky horse immediately after racing.