Intrapulmonary concentration of enrofloxacin in healthy calves.

To determine the intrapulmonary concentration of enrofloxacin (ERFX) in calves, plasma, bronchoalveolar lavage fluid (BALF) and alveolar cells samples were obtained from clinically healthy calves. Four clinically healthy calves were administered a single dose of ERFX (5 mg/kg) by subcutaneous injection. Samples of plasma were obtained for each subjects at 0 (before administration), 1 and 2 hr after administration of ERFX. Samples of BALF were obtained from each subject at 0, 1 and 2 hr after administration of ERFX. This examination was conducted two times, one week apart. The mean EFRX concentrations in plasma at 1 and 2 hr after administration were l.23 and 1.29 µg/ml, respectively. The mean EFRX concentrations in pulmonary epithelial lining fluid (ELF) at 1 and 2 hr after administration 8.53 µg/ml and 9.42 µg/ml, respectively. The mean ERFX concentrations of alveolar cells in BALF at 1 and 2 hr after administration were 4.04 µg/ml and 5.19 µg/ml, respectively. These results suggest that the ERFX concentrations in ELF and alveolar cells concentrations in BALF at 1 and 2 hr after administration were higher than the plasma concentrations.