Effect of an antimicrobial stewardship intervention on the prescribing behaviours of companion animal veterinarians: A pre-post study

Background Antimicrobial stewardship is a cornerstone of efforts to combat antimicrobial resistance. We evaluated the impact of a formal discussion of antimicrobial stewardship for dogs and cats on systemic antimicrobial prescribing behaviours among companion animal veterinarians. Methods Electronic health records including information about the prescription of antimicrobials were collected from a multisite UK veterinary practice between 2017 and 2020. We undertook interrupted time series analysis using a quasi-Poisson model to compare the pre- and postintervention change in level and slope for multiple outcomes. Results After the intervention, there were sustained reductions in the prescription rate of cefovecin to cats and metronidazole to dogs and increases in amoxicillin-clavulanic acid prescribing. There was no evidence for an immediate change in overall prescribing rates in either species, although rates increased over the 12 months after the intervention. There was a transient increase in the proportion of dogs who had their weight recorded at the time of prescription. Results suggest decreases in the prescription of off-licence antimicrobials in both species and the likelihood of underdosing in dogs. Conclusions Discussion of antimicrobial stewardship is more likely to influence the antimicrobial choice than whether to prescribe or not. Interventions may benefit by focusing on appropriate antimicrobial selection rather than overall prescription frequency.