Clinical and laboratory evaluation of horses after intraperitoneal injection of lipopolysaccharide (LPS)

Horses are very sensitive to Gram-negative bacterial lipopolysaccharides (L PS) which, when introduced into the blood stream, induce several responses mediated by endogenous pro-inflammatory mediators originating from bacterio lysis or granulocyte disintegration. Intraperitoneal LPS injection was used to mimic the proposed route of endotoxin travel in clinical cases. The cli nical signs and laboratory findings demonstrated a dose- dependent effect a nd were more consistently observed with 500 ng/kg of LPS. We conclude that intraperitoneal injection of LPS produces the same endotoxic status as obta ined by systemic injection of LPS, even during the initial phase.