title: Comparison of clinical, microbiologic, and clinicopathologic findings in horses positive and negative for Clostridium difficile infection.
abstract: OBJECTIVE
  To compare clinical, microbiologic, and clinicopathologic findings among horses infected with Clostridium difficile that had toxin A in their feces, horses with evidence of C difficile infection that were negative for toxin A in their feces, and horses with diarrhea that were negative for C difficile infection.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  292 horses and foals with diarrhea.
  
  
  METHODS
  Feces were submitted for microbial culture and tested for the C difficile antigen glutamate dehydrogenase and for toxin A with a commercial ELISA.
  
  
  RESULTS
  Horses with toxin A in their feces had higher band neutrophil count, rectal temperature, hospitalization time prior to the onset of diarrhea, and total hospitalization time than did horses without evidence of C difficile infection, and 32 of the 33 (97%) horses with toxin A in their feces had received antimicrobials prior to the onset of diarrhea. Horses with toxin A in their feces had a significantly higher mortality rate than did horses negative for toxin A in their feces. Sensitivity and specificity of the ELISA for detection of C difficile antigen were 93% and 88%, when assay results were compared with results of microbial culture following direct plating, and 66% and 93%, when assay results were compared with results of microbial culture following broth enrichment.
  
  
  CONCLUSIONS
  Results provided some evidence that horses positive for toxin A had more severe clinical disease than did horses with evidence of C difficile infection that were negative for toxin A and horses with diarrhea without evidence of C difficile infection.
authors.affiliation: Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Ruby
authors.forename: K Gary
authors.initials: KG
authors.lastname: Magdesian
authors.forename: Philip H
authors.initials: PH
authors.lastname: Kass
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000302:isolation & purification*; D016360:Clostridioides difficile / Q000302:isolation & purification / Q000378:metabolism; D003430:Cross-Sectional Studies; D003967:Diarrhea / Q000382:microbiology / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D004761:Enterocolitis, Pseudomembranous / Q000382:microbiology / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D004768:Enterotoxins / Q000302:isolation & purification*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary; D005243:Feces / Q000737:chemistry* / Q000201:enzymology / Q000382:microbiology; D005260:Female; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D006734:Horse Diseases / Q000382:microbiology / Q000401:mortality / Q000473:pathology*; D006736:Horses; D006760:Hospitalization; D008297:Male; D012720:Severity of Illness Index
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile; D005969:Glutamate Dehydrogenase