You can lock the gate for seven days, but you can t stop Baytril 100 (enrofloxacin) Injectable.

Transcription

1 You can lock the gate for seven days, but you can t stop Baytril 100 (enrofloxacin) Injectable.

2 Baytril 100 (enrofloxacin) Injectable field trial investigates the lock the gate BRD treatment regimen. Often, practitioners resort to a lock the gate BRD treatment regimen that includes a post-treatment moratorium (PTM). PTM is a variable, 3- to 10-day waiting period following initial BRD treatment and prior to BRD retreatment. Practitioners use a PTM hoping to: Avoid treating cattle that do not need retreatment. Provide sick cattle time to respond to the initial BRD treatment. Reduce hospital congestion and costs associated with retreatment. Because of the mode of action of some drugs, time-dependent drugs specifically, they need to stay above the MIC (minimum inhibitory concentration) in the animal for several days. But Baytril 100 is a concentration-dependent drug. Its active ingredient, enrofloxacin, kills bacteria so extended duration of the effective concentration is not necessary. To confirm this point, Bayer put Baytril 100 and Draxxin (tulathromycin) to the test in a head-to-head comparison Southeastern, high-risk sale barn calves were purchased, commingled and shipped to Nebraska during November. Each calf was treated metaphylactically with Micotil (tilmicosin) at initial processing. 199 calves were randomly assigned to study groups as they became ill with BRD. 99 calves were allocated to the Draxxin group, 100 calves to the Baytril 100 group. The 28-day study utilized a 7-day PTM. After the 7-day PTM, calves were re-treated for BRD according to established practices. Severe winter weather conditions prevailed. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

3 Results Baytril 100 proved successful in a PTM treatment regimen. As the following figures demonstrate, Baytril 100 performed effectively in a BRD treatment regimen utilizing a PTM. Figure 1. Days to Retreatment 1 Number of Head PTM Days Though the Draxxin and Baytril 100 groups had 41 and 49 retreatments, and 20 and 27 second retreatments, respectively, there were no significant statistical differences between the two groups. 92% of Baytril 100 retreatments occurred in the first seven days following PTM, consolidating retreatment time and labor. Draxxin retreatments continued for 18 days following PTM. Cattle intended for human consumption must not be slaughtered within 28 days from the last treatment.

4 Table 1A. Average Daily Gain (ADG) 1 Group ADG (Deads in) (lb) ADG (Deads out) (lb) Baytril Draxxin As a further indicator of BRD response, the ADG of the calves was measured. The results of the two groups were comparable, which provides further evidence that Baytril 100 (enrofloxacin) Injectable can be used successfully in a 7-day PTM scenario. Table 1B. Case Fatalities 1 Group Head Case Fatalities (7-day PTM) Case Fatalities (All BRD) Baytril Draxxin By the end of this study, the Baytril 100 group had the vast majority of its retreatments in a concise 7-day period. Baytril 100 can be used successfully in a 7-day PTM. A withdrawal period has not been established in pre-ruminating calves. Do not use in calves to be processed for veal.

5 Whether used in a pull and treat or lock the gate regimen, Baytril 100 works. In the laboratory,* Baytril 100 kills BRD pathogens in one to two hours, 2,3 reducing the population so extended duration of the effective concentration is not necessary. Drug Plasma Concentration (μg/ml) Baytril 100 has a classic concentration-dependent profile M. haemolytica MIC 90 = μg/ml* 4 Pharmacokinetics: 12.5 mg/kg enrofloxacin with active metabolite* Hours Post-SubQ Injection Baytril 100 is concentration-dependent, reaching therapeutic levels at the site of infections in lungs within 1 2 hours* 3 and peak killing concentration in less than 5 hours in the lungs.* 5 Baytril 100 is bactericidal and kills all four of the major BRD-causing pathogens. Despite the fact that Baytril 100 does not remain on board for seven days, it s effective because of its concentration-dependent killing properties. And once bacteria are dead, they re dead. *The clinical significance of in vitro data has not been demonstrated. MPC 90* 3 Extra-label use of this product in food-producing animals is prohibited.

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10 1 Data on file. 2 Blondeau JM, Borsos S, Blondeau LD, et al. (2005). The killing of clinical isolates of Mannheimia haemolytica (MH) by enrofloxacin (ENR) using minimum inhibitory and mutant prevention drug concentrations and over a range of bacterial inocula. In: ASM Conference on Pasteurellaceae; October 2005; Kohala Coast, Big Island, Hawaii: American Society of Microbiology; Abstract B12. 3 Blondeau JM, Borsos SD, Hesje CH, et al. (2007). Comparative killing of bovine isolates of Mannheimia haemolytica (MH) by enrofloxacin, florfenicol, tilmicosin and tulathromycin using the measured minimum inhibitory concentration (MIC) and mutant prevention concentration (MPC) drug values. In: International Meeting of Emerging Diseases and Surveillance (IMED); Vienna, Austria; February 23-25, 2007; Figures Data on file. 5 Davis JL, Foster DM, Papich MG. (2007). Pharmacokinetics and tissue distribution of enrofloxacin and its active metabolite ciprofloxacin in calves. J Vet Pharmacol Ther. 30(6): Bayer HealthCare LLC, Animal Health, Shawnee Mission, Kansas Bayer, the Bayer Cross, Baytril and Right the first time are trademarks of Bayer. Draxxin is a registered trademark of Zoetis. Micotil is a registered trademark of Eli Lilly and Company. BL15177