An experimental model of intraabdominal abscess in the rat

Suitable small animal models of intraabdominal abscess are not available. We have developed a reliable model of intraabdominal abscess in the rat by fasting the animal overnight, devascularizing and ligating the cecum, and injecting 2.5 X 10(8) Escherichia coli and 2.5 X 10(9) Bacteroides fragilis into the ligated cecum. This model results in 39% coli acute mortalities within 48 hours from acute peritonitis, and abscess in 76% of survivals. Subsequent abscesses are 1.0--1.5 ml in volume and contain 4 X 10(8) E coli/ml of pus and 1.4 X 10(9) B fragilis/ml. This model allows chronic evaluation of sepsis in small animals and provides a convenient means to study the abscess microenvironment.