Bladder rupture in late-pregnancy mares: Four cases

This case series reports four late pregnancy broodmares that were diagnosed with bladder rupture. The initial presentations were abdominal discomfort (n = 3) and dystocia (n = 1). All mares (n = 4) were overdue or at their expected time of delivery. Three mares showed clinical signs related to bladder rupture: pollakiuria (n = 2) and hematuria (n = 1). At the time of diagnosis, three mares had increased peritoneal fluid creatinine, the mean peritoneal: serum creatinine ratio was 4.1, and the bladder tear was observed via cystoscopy in 3 cases. Two mares were discharged from the hospital. Complete evaluation of the clinical, clinicopathological, repeated ultrasonographic, and cystoscopic examination was necessary to diagnose this condition. In three of the four cases there was no accumulation of free peritoneal fluid upon initial examination, which may delay the diagnosis for 2-3 days until the uroperitoneum can be diagnosed. Broodmares past their expected foaling date, showing signs of colic and pollakiuria should be suspected of bladder rupture.