Antimicrobial susceptibilities of canine Clostridium difficile and Clostridium perfringens isolates to commonly utilized antimicrobial drugs

Stanley L Marks, Elizabeth J. Kather

Research output: Contribution to journalArticle

50 Scopus citations


Clostridium difficile and Clostridium perfringens are anaerobic, Gram-positive bacilli that are common causes of enteritis and enterotoxemias in both domestic animals and humans. Both organisms have been associated with acute and chronic large and small bowel diarrhea, and acute hemorrhagic diarrheal syndrome in the dog. The objective of this study was to determine the in vitro antimicrobial susceptibilities of canine C. difficile and C. perfringens isolates in an effort to optimize antimicrobial therapy for dogs with clostridial-associated diarrhea. The minimum inhibitory concentrations (MIC) of antibiotics recommended for treating C. difficile (metronidazole, vancomycin) and C. perfringens-associated diarrhea in the dog (ampicillin, erythromycin, metronidazole, tetracycline, tylosin) were determined for 70 canine fecal C. difficile isolates and 131 C. perfringens isolates. All C. difficile isolates tested had an MIC of ≤1 for both metronidazole and vancomycin. Ninety-five percent (124/131) of C. perfringens isolates tested had an MIC for ampicillin of ≤0.125μg/ml. Two C. perfringens isolates had an MIC of ≥256μg/ml for both erythromycin and tylosin. A third C. perfringens isolate had an MIC of 32μg/ml for metronidazole. Based on the results of this study, ampicillin, erythromycin, metronidazole, and tylosin appear to be effective antibiotics for the treatment of C. perfringens-associated diarrhea, although resistant strains do exist. However, because there is limited information regarding breakpoints for veterinary anaerobes, and because intestinal concentrations are not known, in vitro results should be interpreted with caution.

Original languageEnglish (US)
Pages (from-to)39-45
Number of pages7
JournalVeterinary Microbiology
Issue number1
StatePublished - Jun 24 2003



  • Clostridium spp.
  • Diarrhea
  • Dog
  • Drug resistance
  • MIC

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Microbiology
  • veterinary(all)

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