Ruptured urinary bladder in a post-parturient cow.

Rupture of the urinary bladder at the time of parturition occurred in a 2 year old Angus cow. Anamnesis included a dystocia followed by a gradual (16 days) onset of anorexia and abdominal distension. Prominent findings on the physical examination were marked dehydration, symmetrical distension of the lower abdomen with ascitic fluid, pneumoperitoneum, absence of rumen contractions, and constipation. Significant laboratory findings were elevations of plasma protein, serum urea nitrogen (SUN) and creatinine, hypochloremia, hyponatremia, hyperkalemia, and metabolic acidosis. The ascitic fluid was present in large quantities (50 liters) and had a markedly elevated urea nitrogen and creatinine concentration when compared to serum values for these substances. Parotid salivary secretion had a reversal of the normal sodium: potassium ratio which was attributed to an increase in aldosterone levels brought about by the hyponatremia. A ventral tear in the urinary bladder was successfully repaired by laparotomy.