Pharmacokinetics after intravenous, subcutaneous, and oral administration of enrofloxacin to alpacas.

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 X 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 gram-positive 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. [ABSTRACT FROM AUTHOR]