Uroperitoneum in a preparturient mare

Uroperitoneum is an insidious and potentially fatal disease process in horses.1,2 Although most commonly diagnosed in foals,1,3 uroperitoneum secondary to bladder rupture is uncommon in adult horses and reportedly associated with parturition, 2,4-7 urolithiasis,8,9 or trauma.10 Clinical signs typically present from 48 to 72 hours after rupture and consist of lethargy, anorexia, variable urination (anuria, pollakiuria, or stranguria), tachycardia, tachypnea, abdominal distension, or cardiac arrest.3 Hematologic findings often include azotemia, hyperkalemia, hyponatremia, hypochloremia, and metabolic acidosis.3 This report describes uroperitoneum secondary to urinary bladder rupture in a preparturient mare, that to the authors’ knowledge, has not previously been reported. This case underscores the importance of including uroperitoneum after urinary bladder rupture as a differential for late-term pregnant mares and highlights the possibility for safe use of maternal dexamethasone treatment after 335 days of pregnancy to hasten fetal maturity prior to Caesarean section.