Antimicrobial use in equine patients at a veterinary teaching hospital in the northeastern United States reveals opportunities for enhanced stewardship

Objective To assess the use of systemic antimicrobial agents in equine patients and identify areas where their use could be reduced. Methods A retrospective study evaluating the electronic medical records for all equine visits in which systemic antimicrobials were given at a veterinary teaching hospital for 1 year (2021). Negative binomial regression analysis was used to evaluate factors associated with antimicrobial prescription rate. Results Systemic antimicrobials were prescribed for 33.5% (543 of 1,622) of equine visits. For most visits (89.1%), ≤ 3 antimicrobials were given. The antimicrobial prescription rate was higher in patients with confirmed or suspected infection and in patients that died or were euthanized. Highest-priority critically important antimicrobials were used infrequently (13.6% [74 of 543]). Equine patients undergoing clean surgeries (n = 122) received antimicrobials on the day of surgery, with many receiving > 24 hours of treatment (65). Approximately 24% of nonsurgical patients received antimicrobials when there was no evidence of infection. Culture was performed infrequently (15.7%). Conclusions Systemic antimicrobials were given during a third of the equine visits in 2021. The limited use of highest-priority critically important antimicrobials suggests that clinicians were not using these medications for first-line treatment. Areas for improvement include documenting the clinician’s justification for antimicrobial use along with type, duration, and reasons for de-escalation and/or escalation of therapy; reducing perioperative use, especially for clean surgeries; and increasing the submission of samples for culture. Clinical Relevance Antimicrobial resistance continues to be a global concern, and veterinarians can reduce the use of antimicrobials by critically evaluating their own use and modifying behaviors to align with current evidence-based recommendations.