β-Lactam and metronidazole administration are risk factors for carbapenemase-producing Enterobacterales acquisition in hospitalized dogs

Am J Vet Res. 2025 Dec 10;87(3):ajvr.25.09.0344. doi: 10.2460/ajvr.25.09.0344. Print 2026 Mar 1.

Abstract

Objective: To identify risk factors for carbapenemase-producing, carbapenem-resistant Enterobacterales (CP-CRE) acquisition in dogs and cats during hospitalization.

Methods: A retrospective case-control study evaluating risk factors for acquiring CP-CRE during hospitalization in dogs and cats admitted from June 1, 2021, through September 30, 2023, was performed. Cases consisted of patients testing negative for CP-CRE at admission and positive prior to discharge. Control patients testing negative at admission and throughout hospitalization were matched to cases with a 3:1 ratio by species, managing service, and date and number of hospitalized days of CP-CRE testing. Patient demographics and characteristics were extracted from the electronic medical record. Conditional logistic regression modeling was performed to assess the association between these variables and being a case.

Results: 46 case dogs and 4 case cats were investigated. Due to the small number of cats, risk factors were only analyzed for dogs. On multivariable analysis, the odds of CP-CRE acquisition were significantly greater for dogs receiving a β-lactam antimicrobial (OR, 4.71; 95% CI, 1.32 to 16.82) or metronidazole (OR, 6.38; 95% CI, 1.71 to 23.74). All 4 case cats had received a β-lactam antimicrobial, and the majority (3 of 4 case cats) had received acid suppressants, were admitted from the emergency service, and had a central venous catheter or peripheral sampling line.

Conclusions: Receiving a β-lactam antimicrobial or metronidazole was an independent risk factor for CP-CRE acquisition in hospitalized dogs.

Clinical relevance: These findings highlight the importance of antimicrobial stewardship.

Keywords: antimicrobial stewardship; carbapenemase-producing carbapenem-resistant Enterobacterales; epidemiology; metronidazole; β-lactam antimicrobial.

MeSH terms

  • Animals
  • Anti-Bacterial Agents* / administration & dosage
  • Anti-Bacterial Agents* / adverse effects
  • Bacterial Proteins / metabolism
  • Carbapenem-Resistant Enterobacteriaceae*
  • Case-Control Studies
  • Cat Diseases* / microbiology
  • Cats
  • Dog Diseases* / drug therapy
  • Dog Diseases* / microbiology
  • Dogs
  • Enterobacteriaceae Infections* / microbiology
  • Enterobacteriaceae Infections* / veterinary
  • Enterobacteriaceae* / drug effects
  • Enterobacteriaceae* / enzymology
  • Female
  • Hospitalization
  • Male
  • Metronidazole* / administration & dosage
  • Metronidazole* / adverse effects
  • Metronidazole* / therapeutic use
  • Retrospective Studies
  • Risk Factors
  • beta-Lactamases / metabolism
  • beta-Lactams* / administration & dosage
  • beta-Lactams* / adverse effects
  • beta-Lactams* / therapeutic use

Substances

  • Metronidazole
  • carbapenemase
  • beta-Lactamases
  • Anti-Bacterial Agents
  • beta-Lactams
  • Bacterial Proteins