ALTERATIONS IN CLINICAL, HEMATOLOGICAL AND METABOLIC VARIABLES IN BOVINE NEONATAL ENDOTOXEMIA

Endotoxemia is an important cause of morbidity and mortality in the ne onate. Although many models are used to study the problem, none comple tely simulates the natural disease. To more clearly define a bovine ne onatal endotoxemia model we studied the effects of dose of endotoxin o n clinical, hematological and biochemical variables. Thirty-four neona tal calves were administered Escherichia coli endotoxin (LPS) at 0 (0, 90% Saline solution), 0.2, 2.0 or 20 mu g/kg, by either IV bolus or in fusion over 50 minutes. Variables monitored included mean arterial blo od pressure (MAP), leukocyte (WBC) count, plasma glucose and lactate c oncentrations and clinical status. All LPS-treated calves displayed si milar clinical signs within one hour. Dose-dependent differences in re sponse to LPS among groups became evident over time. Substantial dose- dependent changes in attitude, appetite, mucous membrane character, ca pillary refill time, MAP, plasma glucose and lactate concentrations, a nd WBC count were noted in LPS-treated calves. Higher doses of LPS ind uced a more prolonged clinical response and significantly (p < 0.05) g reater hypotension, lacticemia and hypoglycemia. While dose altered th e response to endotoxin, the method of administration had no overall e ffect on the variables measured.