Exercise-induced Acute Abdominal Haemorrhage due to Iliopsoas Trauma in Racing Greyhounds.

Post-mortem examination of 74 racing greyhounds with sudden, unexpected death was undertaken at the Veterinary School, University of Nottingham, UK, from 2015 to 2019. These investigations revealed severe, acute haemoabdomen with extensive retroperitoneal haemorrhage and an underlying severe, unilateral iliopsoas tear in four cases (5.4%). In all four cases, unilateral trauma and haemorrhage affecting the right iliopsoas muscle was common near the caudal insertion. Despite the acute clinical event, three cases demonstrated histological evidence of previous muscle damage with muscular regeneration, fibrosis and evidence of chronic haemorrhage. To our knowledge, this is the first detailed description of exercise-induced trauma to the iliopsoas muscle leading to extensive haemoretroperitoneum and haemoabdomen with subsequent hypovolaemic shock and death in racing greyhounds.