Detection of pathogens in blood or feces of adult horses with enteric disease and association with outcome of colitis

Background Rates of detecting ≥1 potential enteric pathogens (PEP) or toxins (PEP-T) in feces, blood, or both of horses ≥6 months of age with enteric disease and impact of multiple detections on outcome of horses with colitis has not been reported. Objective To determine detection rates of PEP/PEP-T in feces, blood, or both of horses with enteric disease and effect of detecting multiple agents on outcome of horses with colitis. Animals Thirty-seven hundred fifty-three fecal samples submitted to IDEXX Laboratories and 239 fecal and blood samples submitted to Michigan State University's Veterinary Diagnostic Laboratory (MSUVDL). Methods Retrospective evaluation of PEP/PEP-T testing results was performed to determine rates of detection of 1 or more PEP/PEP-T. Impact of detecting multiple agents on outcome was assessed in 239 horses hospitalized for colitis. Results One or more PEP/PEP-T was detected in 1175/3753 (31.3%) and 145/239 (60.7%) of samples submitted to IDEXX Laboratories and MSUVDL, respectively. In a hospitalized cohort, survival to discharge was lower (76%) in horses with 1 agent, compared to horses with either no (88%) or multiple (89%) agents. There was no difference (P = .78) in days of hospitalization between horses with 0 (1-17), 1 (1-33), and > 1 positive (1-20) result. There was no difference in cost of hospitalization (P = .25) between horses with 0 ($2357, $1110-15 553), 1 ($2742, $788-11 005), and >1 positive ($2560, $1091-10 895) result. Conclusions and clinical importance Detection rates of PEP/PEP-T in horses with colitis vary with cohorts and tests performed. Detection of more than 1 PEP or PEP-T did not affect outcome.