CP and colitis: All horses underwent Salmonella Polymerase Chain Reaction (PCR) testing (3 samples collected at ≥12 hour intervals), while a combined equine diarrhea PCR panel was only performed in 4 of 5 horses with diarrhea (Equine Diarrhea Panel, Research and Diagnostic Core Facility, University of California, Davis: Coronavirus; Clostridium difficile toxins A and B; Clostridium perfringens (CP) antigen, CP alpha toxin, CP beta toxin, CP beta2 toxin, CP cytotoxin (netF), CP enterotoxin; Lawsonia intracellularis; Neorickettsia risticii and Salmonella) to identify potential etiologies of their colitis.