Intestinal bacterial overgrowth includes potential pathogens in the carbohydrate overload models of equine acute laminitis. Academic Article uri icon


  • Carbohydrate overload models of equine acute laminitis are used to study the development of lameness. It is hypothesized that a diet-induced shift in cecal bacterial communities contributes to the development of the pro-inflammatory state that progresses to laminar failure. It is proposed that vasoactive amines, protease activators and endotoxin, all bacterial derived bioactive metabolites, play a role in disease development. Questions regarding the oral bioavailability of many of the bacterial derived bioactive metabolites remain. This study evaluates the possibility that a carbohydrate-induced overgrowth of potentially pathogenic cecal bacteria occurs and that bacterial translocation contributes toward the development of the pro-inflammatory state. Two groups of mixed-breed horses were used, those with laminitis induced by cornstarch (n=6) or oligofructan (n=6) and non-laminitic controls (n=8). Cecal fluid and tissue homogenates of extra-intestinal sites including the laminae were used to enumerate Gram-negative and -positive bacteria. Horses that developed Obel grade2 lameness, revealed a significant overgrowth of potentially pathogenic Gram-positive and Gram-negative intestinal bacteria within the cecal fluid. Although colonization of extra-intestinal sites with potentially pathogenic bacteria was not detected, results of this study indicate that cecal/colonic lymphadenopathy and eosinophilia develop in horses progressing to lameness. It is hypothesized that the pro-inflammatory state in carbohydrate overload models of equine acute laminitis is driven by an immune response to the rapid overgrowth of Gram-positive and Gram-negative cecal bacterial communities in the gut. Further equine research is indicated to study the immunological response, involving the lymphatic system that develops in the model.

published proceedings

  • Vet Microbiol

author list (cited authors)

  • Onishi, J. C., Park, J., Prado, J., Eades, S. C., Mirza, M. H., Fugaro, M. N., Hggblom, M. M., & Reinemeyer, C. R.

citation count

  • 7

complete list of authors

  • Onishi, Janet C||Park, Joong-Wook||Prado, Julio||Eades, Susan C||Mirza, Mustajab H||Fugaro, Michael N||Häggblom, Max M||Reinemeyer, Craig R

publication date

  • October 2012