Antibiotics prescribing patterns and association with system-specific pathologies in equine veterinary practice: Insights from a 12-year study at a veterinary teaching hospital.

Antibiotic prescribing in equine veterinary practice varies depending on the specific body system affected, with certain high-priority antibiotics used more commonly in treating particular diseases. A 12-year retrospective study at a veterinary teaching hospital analyzed these patterns to identify opportunities for more prudent and targeted antimicrobial use.

Study Overview and Objectives

• The study reviewed 1315 cases of adult equids (horses, donkeys, and mules) treated at the University of Pisa Veterinary Teaching Hospital between 2011 and 2023.
• The primary objective was to analyze antibiotic prescribing patterns in equine internal medicine, with a focus on usage of Highest Priority Critically Important Antimicrobials (HPCIAs).
• It aimed to associate antibiotic use with specific system-level pathologies to understand factors influencing antimicrobial choice.

Methods

• A retrospective review of medical records was conducted, extracting data including:
  • Antimicrobial classes prescribed
  • Characteristics of the patients (type of equid, condition)
  • Disease localization by body system and pathology type
• Use of statistical analysis to examine associations between antibiotic class usage and system-specific diseases over the 12-year period.

Key Findings

• Variation by Body System: Antibiotic use significantly varied by system-specific pathology (p < 0.001).
  • Highest antibiotic use was seen in integumentary (skin), ocular (eye), and respiratory conditions.
• Antibiotic Classes:
  • Aminoglycosides were the most frequently used antibiotic class.
  • Tetracyclines and fixed-dose combinations (multi-antimicrobial preparations) were also commonly used.
  • Usage patterns of antibiotic classes shifted significantly over time (p < 0.001), indicating changes in prescribing behavior or disease trends.
• Disease-Specific Usage Patterns:
  • Ceftiofur and gentamicin predominated in treating pneumonia and pleuropneumonia.
  • Oxytetracycline was mainly used for piroplasmosis, a tick-borne disease.
  • Tobramycin was primarily prescribed for corneal ulcers.
  • Combination therapy, especially gentamicin-ceftiofur, was commonly employed for respiratory infections.

Implications for Antimicrobial Stewardship

• The findings highlight variability in prescribing practices linked to specific diseases and body systems.
• The frequent use of HPCIAs, particularly aminoglycosides and tetracyclines, signals a need for careful evaluation to balance effective treatment with antimicrobial resistance risks.
• There is a clear opportunity to optimize antibiotic use through targeted Antimicrobial Stewardship (AMS) programs, which could include:
  • Implementation of evidence-based diagnostic tools to guide more precise antibiotic selection.
  • Educational initiatives to inform veterinarians about prudent antimicrobial use.
  • Regular monitoring and feedback on prescribing patterns to encourage best practices.

Conclusion

• This comprehensive 12-year study provides valuable insights into the patterns of antibiotic use in equine veterinary practice.
• It underscores the importance of tailoring antibiotic therapies according to the specific pathology and body system affected.
• By focusing stewardship efforts on these findings, veterinary practices can improve treatment efficacy while mitigating the development and spread of antimicrobial resistance.