Evaluation of the treatment efficacy of generic enrofloxacin compared to pioneer enrofloxacin for first treatment of naturally occurring bovine respiratory disease in a commercial feedlot

Abstract

The primary objective of this study was to compare the treatment effectiveness of generic enrofloxacin (Tenotryl™ (enrofloxacin) injectable solution; TEN) to pioneer enrofloxacin (Baytril® 100; BAY) for first treatment of naturally occurring bovine respiratory disease (BRD) on subsequent health outcomes in a commercial feedlot. Five hundred cattle identified with BRD by pen riders with rectal temperature ≥ 104.0°F (40°C) were randomized to TEN or the BAY in a 1:1 ratio within each lot. Cattle treated for BRD were returned to their home pen and monitored for 60 days to observe subsequent health outcomes. Cattle were categorized by type (dairy-beef cross or traditional beef breed). General and generalized linear mixed models were used for statistical analyses. There were no differences in first treatment success (64.29% vs 58.16%; P = 0.19) or case fatality risk (10.97% vs 10.65%; P = 0.91) comparing the TEN group to the BAY group respectively. Traditional beef breed cattle had greater body weight at time of enrollment (890.3 lb vs 749.1 lb; P < 0.01) and greater third treatment success (84.44% vs 41.67%; P < 0.01) compared to the dairy-beef cross cattle. There were no differences in health outcomes in cattle administered Tenotryl compared to Baytril 100 for first treatment of BRD in commercial feedlot cattle. From an efficacy perspective, practitioners should be able to use these products interchangeably based upon the results of the study. Additional research on general animal health outcomes of dairy-beef crosses is needed for the industry.