Antimicrobial Resistance in Bovine Respiratory Disease: Prevalence, Impact, and Strategies for Reducing Risk

Presentation Description / Summary: Bovine respiratory disease (BRD) is the most common and costly disease of beef cattle in North America. In feedlots, BRD is responsible for 75% of all morbidity and 50-75% overall mortality. Approximately 16.2% of all cattle entering feedlots will be diagnosed with BRD and 2% will die. In stocker cattle, BRD morbidity occurs far more frequently than what is commonly seen in feedlot cattle and is estimated to be responsible for 90% of all morbidity and mortality in these operations. As a result, it is not unusual to see morbidity risk exceed 75% in certain cohorts of animals. Economically, BRD costs the beef industry $2-4 billion annually with 20% of total losses due to medication costs and 80% of total losses due to reduced carcass weight and poor carcass quality. While multiple factors play a role in the development of BRD, bacteria, particularly Mannheimia haemolytica, are ultimately responsible for the clinical signs seen in affected cattle. As a result, antimicrobials are a mainstay of therapy. Unfortunately, the stocker and feedlot segments have been encountering issues with antimicrobial resistance in Mannheimia haemolytica and, based on recently published data, the isolation of strains of Mannheima haemolytica that are resistant to multiple antimicrobials is becoming a more frequent occurrence. The purpose of this presentation is to review the current literature as it pertains resistance in bacterial BRD pathogens and how we might use this information to develop judicious antimicrobial use strategies in the future.

Learner Outcomes: Understand the prevalence of resistance in bacterial BRD pathogens in dairy and beef cattle populations Understand how antimicrobial resistance affects animal health and welfare Develop judicious antimicrobial use strategies understanding the high prevalence of resistance