Diagnostic peritoneal lavage before and after abdominal surgery in dogs.

Complete blood cell counts and peritoneal lavage (PL) were done 2 days before and 2 days after abdominal surgery. Abdominal surgery consisted of intestinal resection/anastomosis and cystotomy in 18 dogs in group 1 and gastrotomy, pyloromyotomy, and repair of diaphragmatic laceration in 20 dogs in group 2. Insertion of the dialysis catheter for PL preoperatively in a right paramedian location resulted in more PL samples contaminated with blood than when the catheter was inserted on the abdominal midline. The number of nucleated cells found in PL fluid when the catheter was inserted in a right paramedian location was not significantly different (P less than 0.05) from that observed in PL fluid collected after insertion of the catheter through the abdominal midline. The predominant cell type in preoperative PL fluid was the segmented neutrophil. In groups 1 and 2, WBC counts and nucleated cell counts in PL fluid were significantly increased (P less than 0.05) postoperatively. Segmented neutrophils and macrophages were most frequently present in postoperative PL fluid. Degenerative neutrophils in postoperative PL fluid were associated with the appearance of immature neutrophils in the blood and increased rectal temperature. Dogs with these findings appeared to have more peritoneal inflammation at necropsy than did others in their groups. Concentrations of alkaline phosphatase, alanine aminotransferase, amylase, and creatinine in preoperative PL fluid were extremely low. Except for creatinine in group 2, all of these were significantly increased (P less than 0.05) postoperatively. The complication rate associated with the performance of PL on dogs postoperatively was not greater than that which was observed preoperatively.