Plasma Endotoxin Concentrations in Clinically Normal and Potentially Septic Equine Neonates

Plasma endotoxin concentrations were measured at 1 to 2 and 5 to 6 days of age in clinically normal foals and in potentially septic neonatal foals admitted to North Carolina State University's Veterinary Teaching Hospital for a variety of conditions. In 1 to 2 and 5 to 6 day old normal foals, median plasma endotoxin concentrations were 2.17 (range, 1.61–2.54; n = 6) and 2.89 (range, 2.61–3.50; n = 7) endotoxin units/mL (EU/mL), respectively. Median plasma endotoxin concentration in potentially septic foals with negative blood cultures or gram positive isolates (n = 8) was 2.73 (range, 0.59–4.04) EU/mL. In hospitalized foals with gram negative isolates (n = 6), median plasma endotoxin concentration was 78.06 (range, 0.76–2,696.41) EU/mL, but individual endotoxin values were only increased in foals that were extremely sick and died within hours of sampling. Plasma endotoxin concentrations were significantly greater in foals with sepsis scores ≥ 11 compared with foals with sepsis scores ≤ 10. Increased plasma endotoxin concentrations appear to predict an unfavorable outcome in septic foals, but normal endotoxin concentrations do not appear to have any predictive value. (Journal of Veterinary Internal Medicine 1993; 7:296–302. Copyright © 1993 by the American College of Veterinary Internal Medicine.)