Objective—To determine plasma concentrations of enrofloxacin and the active metabolite ciprofloxacin after PO, SC, and IV administration of enrofloxacin to alpacas.
Animals—6 adult female alpacas.
Procedure—A crossover design was used for administration of 3 single-dose treatments of enrofloxacin to alpacas, which was followed by an observational 14-day multiple-dose regimen. Single-dose treatments consisted of IV and SC administration of injectable enrofloxacin (5 mg/kg) and PO administration of enrofloxacin tablets (10 mg/kg) dissolved in grain to form a slurry. Plasma enrofloxacin concentrations were measured by use of high-performance liquid chromatography. The multiple-dose regimen consisted of feeding a mixture of crushed and moistened enrofloxacin tablets mixed with grain. Behavior, appetite, and fecal quality were monitored throughout the 14-day treatment regimen and for 71 additional days following treatment.
Results—Mean half-life following IV, SC, and PO administration was 11.2, 8.7, and 16.1 hours, respectively. For SC and PO administration, mean total systemic availability was 90.18% and 29.31%, respectively; mean maximum plasma concentration was 3.79 and 1.81 µg/mL, respectively; and area under the curve (AUC) was 50.05 and 33.97 (µg × h)/mL, respectively. The SC or PO administration of a single dose of enrofloxacin yielded a ratio for AUC to minimum inhibitory concentration > 100 for many grampositive and gram-negative bacterial pathogens common to camelids.
Conclusions and Clinical Relevance—The administration of enrofloxacin (5 mg/kg, SC, or 10 mg/kg, PO) may be appropriate for antimicrobial treatment of alpacas. (Am J Vet Res 2005;66:767–771)