Evaluating a Targeted Antimicrobial Stewardship Program to Combat Resistance in a Veterinary Referral Hospital

Antimicrobial resistance is an increasing concern in companion animal practice, yet effective strategies to reduce resistance within referral hospitals remain underexplored. This study investigated whether antimicrobial stewardship interventions, guided by hospital-specific resistance and prescribing data, could improve resistance outcomes in a secondary care veterinary setting. Based on the 2016–2018 findings at the University of Tokyo Veterinary Medical Center, a targeted intervention was developed and implemented in early 2019, and its impact was evaluated through 2024. The intervention included Gram stain–based pathogen estimation, antibiogram-informed prescribing, education, and feedback. By 2020, overall antimicrobial use had decreased by over 50%, substantially reducing carbapenems and fluoroquinolones. The proportion of extended-spectrum β-lactamase–producing Escherichia coli and Klebsiella spp. fell from 53% to 24% and from 78% to 7%, respectively, by 2022. However, methicillin-resistant Staphylococci remained prevalent at around 50%. These results suggest that hospital-tailored stewardship can lead to meaningful reductions in resistance among Gram-negative pathogens, though additional measures may be needed to address persistent resistance in Gram-positive organisms.