Physical and clinical pathological findings associated with experimentally induced rupture of the equine urinary bladder.

Two mature horses were examined for changes in laboratory and physical findings after experimentally induced bladder rupture. The postrupture laboratory diagnostic changes, which provide valuable information for a correct diagnosis are described. Hematology, serum and peritoneal fluid sodium, potassium, calcium, phosphorous, creatinine, urea nitrogen, albumin and peritoneal fluid components were measured and evaluated versus time. Hyponatremia and hyperkalemia occurred, as well as increased concentrations of peritoneal fluid potassium and inorganic phosphorus. In addition, peritoneal fluid creatinine:serum creatinine and peritoneal fluid urea nitrogen:serum urea nitrogen ratios were followed with time. Hematology and cytology of the peritoneal fluid showed an inflammatory response to urine contamination of the abdominal cavity. Physical findings of tachypnea and tachycardia as well as a mild colic were absent until nearly 50 hours postrupture. Based on these findings, it was concluded that the peritoneal fluid creatinine:serum creatinine ratio was the most useful antemortem laboratory diagnostic aid.