Pharmacokinetics of tetracycline after single-dose oral administration in the American alligator (Alligator mississippiensis).

The major objective of the study was to assess the pharmacokinetics of tetracycline administered orally to fasted and nonfasted American alligators (Alligator mississippiensis) at 50 mg/kg. Plasma levels of tetracycline were determined using high-performance liquid chromatography with ultraviolet detection. The concentration versus time curve was analyzed using a compartmental modeling technique. A one-compartment model with first-order absorption and elimination, as well as a lag time to absorption, best described the data. The area under the curve and mean residence time values differed significantly between the fasted and nonfasted groups. Based on the results of this study, tetracycline suspension administered once orally at 50 mg/kg to American alligators is not expected to reach plasma concentrations above the breakpoint minimum inhibitory concentration of 4 microg/ml for susceptible organisms.