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.