The effect of endotoxin and anti-endotoxin serum on synovial fluid parameters in the horse.

INTRODUCTION Septic arthritis in horses of all ages remains a difficult therapeutic challenge. Despite early diagnosis and appropriate vigorous therapy, the prognosis for return to athletic function is gaurded. The trend appears to be towards increased aggressiveness in the treatment of septic arthritis. As this frustrating disease often defies treatment, veterinarians may resort to ill-defined therapeutic methods in the hope of achieving a better response. Literature on the use of equine hyperimmune anti-endotoxin (anti-LPS) serum in the treatment of septic arthritis in horses is based on reports of its use in clinical cases. Anti-LPS plasma has also been used for the treatment of gastroenteritis and endotoxaemia in horses, in cases of haemorrhagic enteric endotoxaemia in dogs and Pseudomonas keratitis in rabbits. However, the conclusions based on clinical studies may be confounded by various factors, including the bacterial agent involved, the method and dose of inoculation, the duration of infection, host immunological defence competence, concurrent systemic disease, pre-existing joint pathology and the treatment protocol employed. The main purpose of this study was to evaluate the use of a commercially available equine hyperimmune antiendotoxin preparation in an induced synovitis model, as well as to define its effects in normal equine joints.