Antimicrobial Use in Bovine Veterinary Medicine in Washington State: Opportunities for Redefining Stewardship

Antimicrobial stewardship is an essential set of practices designed to preserve the efficacy of key antimicrobials to protect the health of humans and other animals as well as the environment. However, these practices vary across different healthcare settings and sectors. To better understand the antimicrobial stewardship practices of bovine veterinarians in Washington State, we used a mixed-methods approach involving three components: 1) an electronic survey including case scenarios where antimicrobials may be used, 2) a group conversation around diagnostics, antimicrobial susceptibility test results interpretation, and resources used for antimicrobial prescription guidance, and 3) exploratory semi-structured interviews covering herd health management and stewardship on farms. The survey included sections on demographics, perceptions around factors contributing to antimicrobial resistance, and treatment recommendations for clinical scenarios. We performed descriptive analysis of survey data and qualitative analysis of the group conversation and interview responses. Thirteen bovine veterinarians completed the survey, twenty were present for the group conversation with eight main contributors and two veterinarians participated in in-depth interviews. When asked to select the treatment they would recommend for the clinical case scenarios presented in the survey, 63.2% of respondents selected the same option as a board-certified veterinary microbiologist. Participants frequently recommended diagnostic tests for mastitis, but often selected empiric antimicrobials for respiratory cases due to the perception that testing is not clinically actionable because of limited legal antibiotic choices in food animal medicine. The veterinarians interviewed emphasized infection prevention and control strategies over antimicrobial use for control of common conditions. They highlighted that antimicrobial stewardship on farms focuses more on management and disease prevention. To further support antimicrobial stewardship in bovine medicine, we should prioritize supporting up-to-date literature reviews for effective treatment of common diseases, investigating clinically actionable diagnostic data on bovine respiratory disease as well as evaluating vaccine efficacy, and developing best practice resources for veterinarians, producers, and herd health workers.