Use of large-scale veterinary data for the investigation of antimicrobial prescribing practices in equine medicine

Equine Vet J. 2017 Jul;49(4):425-432. doi: 10.1111/evj.12638. Epub 2016 Oct 5.


Background: As antimicrobial resistant bacterial strains continue to emerge and spread in human and animal populations, understanding prescription practices is key in benchmarking current performance and setting goals. Antimicrobial prescription (AP) in companion veterinary species is widespread, but is neither monitored nor restricted in the USA and Canada. The veterinary use of certain antimicrobial classes is discouraged in some countries, in the hope of preserving efficacy for serious human infections.

Objectives: The aim of this study was to ascertain the rate of prescription of a number of 'reserved' antimicrobials in a first-opinion US and Canadian horse cohort, and identify trends in their empirical use.

Study design: Retrospective cohort study.

Methods: A large convenience sample of electronic medical records (2006-2012) was interrogated using text mining to identify enrofloxacin, clarithromycin and ceftiofur prescriptions. Time series analysis and logistic regression were used to identify trends and risk factors for prescription.

Results: Prescription of these antimicrobials as a first-line intervention, without culture and sensitivity testing (CST), was common in this population. Enrofloxacin prescriptions were found to increase over the study period, and there was evidence of either a reducing, or static trend in the proportion of reserved APs informed by CST.

Main limitations: Dose adequacy could not be included due to the nature of the data used.

Conclusions: Empirical use of reserved antimicrobials was common in this population, and further advice and guidance should be issued to first-opinion veterinarians to safeguard antimicrobial efficacy.

Keywords: antimicrobial; horse; prescription; resistance.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / administration & dosage
  • Anti-Bacterial Agents / therapeutic use*
  • Canada
  • Horses
  • Humans
  • Practice Patterns, Physicians'*
  • Retrospective Studies
  • Veterinarians
  • Veterinary Medicine / standards
  • Veterinary Medicine / statistics & numerical data*


  • Anti-Bacterial Agents