Plasma endotoxin in horses presented to an equine referral hospital: Correlation to selected clinical parameters and outcomes

• Published in: Equine veterinary journal 2011-09, Vol.43 (5), p.585-591
• Main Authors: Senior, J.M, Proudman, C.J, Leuwer, M, Carter, S.D
• Format: Article
• Language: English
• Subjects: Animals; assay; blood; colic; Colic - blood; Colic - mortality; Colic - pathology; Colic - veterinary; correlation; endotoxaemia; endotoxemia; Endotoxemia - blood; Endotoxemia - mortality; Endotoxemia - pathology; Endotoxemia - veterinary; endotoxin; endotoxins; Female; heart rate; hematocrit; horse; Horse Diseases - blood; Horse Diseases - mortality; Horse Diseases - pathology; Horses; Limulus; Lipopolysaccharides - blood; Male; mortality; Odds Ratio; plasma; regression analysis; risk; Risk Factors
• ISSN: 0425-1644; 2042-3306
• DOI: 10.1111/j.2042-3306.2010.00328.x

Reasons for performing study: Endotoxaemia is frequently presumed on the basis of clinical signs in horses with colic. Objective: Measurements of plasma endotoxin (LPS) are rarely made in clinical cases and there is little information on the correlations between this variable, clinical variables and outcomes. Objectives: To measure LPS levels in plasma of horses presented to the Philip Leverhulme Equine Hospital on admission and daily for up to 4 days and to relate LPS levels to selected clinical parameters, such as heart rate and packed cell volume, and outcomes. Methods: Blood samples were collected and stored at -20°C prior to assay of the plasma using a validated kinetic chromogenic Limulus amoebocyte lysate (LAL) assay. Clinical parameters and outcome variables were collected from hospital records. Associations were determined by Chi-squared test and logistic regression analysis. Results: Daily blood samples were collected from 234 horses. LPS was detected in 26.5% of the study population and in 29% of those horses presented for colic. Horses providing samples with detectable LPS were more likely to die whilst in the hospital than those that did not (P = 0.045). Horses presenting with colic were more likely to have detectable LPS in their plasma than noncolic cases (P = 0.037), although LPS was detected in the plasma of 8 out of 42 noncolic horses. A horse that did not meet the study definition of clinical endotoxaemia was 10 times less likely to provide a positive LPS sample (OR 0.10, 95% CI: 0.05–0.22). Conclusions: The proportion of horses providing samples with detectable LPS was similar to other studies. Potential relevance: LPS was detected in the minority of horses presented with colic. Increased levels of LPS positively correlated with packed cell volume and with risk of mortality in colic cases.