Bovine endotoxicosis - Some aspects of relevance to production diseases. A review

This review describes some circumstances where endotoxins of Gram negative bacteria may be related to the pathogenesis of some common production diseases. Decisive evidence for the pathogentical role of endotoxins remains scarce, and therefore an interdisciplinary background covering epidemiological, biological, biochemical, clinical and experimental aspects is given. Several authors have suggested that endotoxins play a significant role for the development of diseases such as laminitis, abomasal displacement, sudden death syndrome of feed-lot steers ect. While the biological, biochemical and clinical pictures of bovine endotoxicosis is quite well known, and certainly may resemble the clinical and biochemical pictures seen in some of the before mentioned diseases, it is however still not clear how or when endotoxins would gain parenteral access. This review describes excerpts of the biology of endotoxins, key clinical signs and the biochemistry associated to these. It is described how ruminal acidosis may facilitate the translocation of endotoxin from the intestinal/ruminal contents to the portal and eventually the systemic bloodstream. The function of the liver hence becomes central, and the role of hepatic fatty infiltration around parturition is discussed. The review finally suggest that acute ruminal acidosis may be viewed as an analogue to the human syndrome Gut-Derived Infectious Toxic Shock (GITS), where shock is propagated primarily by the translocation of bacterial endotoxin from the gut.