Salmonella spp. fecal shedding detected by real-time PCR in competing endurance horses

Fecal shedding of Salmonella spp. was recently documented in 8% of endurance horses presented to equine referral centers for colic. Previous studies have documented fecal shedding of Salmonella spp. in as few as 0.8% of the general horse population, although horses with colic appear to be at higher risk. Fecal Salmonella spp. shedding before and after endurance horse competitions has not been evaluated. Fecal samples were collected from 204 horses during three separate 100 mile endurance competitions. Following incubation in selenite broth, 289 fecal samples were tested by real-time PCR analysis for Salmonella spp. Only one post-race sample (0.5% tested positive for Salmonella spp. in this study and no pre-race sample was available from this horse. Results suggest that fecal shedding of Salmonella spp. is uncommon in endurance horses during competitions. Further research is needed to confirm and identify the source of Salmonella spp. infection in endurance horses with colic requiring treatment at referral centers.