Equine Ruptured Bladder in Neonate – NAVLE Study Guide

Overview and Clinical Importance

Uroperitoneum is the accumulation of urine within the peritoneal cavity, most commonly caused by rupture of the urinary bladder in neonatal foals. This condition represents a true medical emergency requiring rapid diagnosis and intervention. Uroperitoneum occurs in approximately 0.2% to 2.5% of foals presenting to equine hospitals and carries significant morbidity if not promptly recognized and treated.

The urinary bladder is affected in approximately 73.1% of cases, the urachus in 21.6%, and the ureter in 5.2% of cases. Understanding the pathophysiology, clinical presentation, and management of this condition is essential for NAVLE success.

Anatomy and Pathophysiology

Relevant Anatomy

The equine bladder is lined with transitional epithelium and composed of two interwoven layers of smooth muscle. The inner layer is oriented in a circular fashion and the outer longitudinal layer provides structural support. Critically, the dorsal aspect of the bladder lacks the longitudinal muscle layer, making it the weakest point and the most common site of rupture.