Efficacy of in-feed antimicrobial medication in the control of pneumonia in cattle: A review

The efficacy of antimicrobial medication in controlling pneumonia when administered in feed or water was reviewed. Only a limited number of antimicrobial drugs have good absorption and bioavailability after oral administration, although for some of these absorption is reduced or delayed when administered with milk or milk replacer. Due to differences in treatment regimes, group sizes, experimental units and randomization procedures, it is not possible to come to any overall conclusions regarding the safety and efficacy of oral antimicrobial medication in the treatment of bovine respiratory disease. However, it is generally accepted that in inappetent pneumonic animals antimicrobial drugs administered in the feed may achieve only subtherapeutic concentrations. The need for additional well-designed randomised experiments of adequate size was emphasised.