Estimated antimicrobial dispensing frequency and preferences for lactating cow therapy by Ontario dairy veterinarians.

In this cross-sectional study, data were collected from responses to a questionnaire on dispensing frequencies of antimicrobials used by dairy practitioners in Ontario in dairy cattle in 2001. Data were validated through clinical case scenarios. Respondents reported using antimicrobials across all categories of importance to human medicine (medically important, Categories I to III) with a diversity of treatment combinations and routes of administration. Respondents anticipated that a request for direct veterinary supervision by producers was dependent on case severity, highlighting the importance of on-farm diagnostic and treatment protocols. Knowledge of the antimicrobials used in lactating cow therapy, and their frequency and reasons for use, will provide baseline information and contribute to antimicrobial stewardship in this food-animal production sector.