Antimicrobial usage in western Canadian cow-calf herds.

While ongoing surveillance and research initiatives have provided some information on antimicrobial use (AMU) in many livestock commodities, there are no recent reports for Canadian cow-calf herds. Antimicrobial use data were collected in 2014 for bulls, cows, and calves from 100 herds participating in the Western Canadian Cow-Calf Surveillance Network. Lameness was the most common reason for treatment in cows and bulls, with oxytetracycline being the treatment of choice. Herd owners were most likely to treat calves before weaning with florfenicol, oxytetracycline, and sulfamethazine for respiratory disease or diarrhea. The most frequently reported reason for antimicrobial use in weaned calves was respiratory disease and the most reported product was florfenicol. While 98% of herds reported treating ≥ 1 animal with antimicrobials, most cattle did not receive antimicrobials for either treatment or disease prevention on participating cow-calf operations.