Abstract: The target of the present study was to investigate the plasma disposition kinetics of tulathromycin in rabbits (n = 20) following a single intravenous (i.v.) bolus or intramuscular (i.m.) injection at a dose rate of 2.5 mg kg-1 B.W. using a parallel design. Plasma samples were collected at appropriate times during a 216 h administration interval and were analyzed using a Microbiological Assay Method. The plasma tulathromycin disposition was best fitted to a Two Compartment Open Model after i.v. dosing. The half-lives of distribution and elimination were 0.31±0.07 and 61.83±8.43 h, respectively. The volume of distribution at steady-state was 10.32±1.26 L kg-1, the total body clearance (Cltot) was 0.13±0.07 L/kg/h and the areas under the concentration-time curves (AUC) was 22.56±2.21 μg/mL/h. Following i.m. administration, the mean t1/2el and AUC values were 103.28±17.65 h and 24.61±2.15 μg/mL/h. The bioavailability was high (102.59±12.82%) with a peak plasma mean concentration (Cmax) of 0.76±0.11 μg mL-1 attained at 0.81±0.06 h (Tmax). The in vitro protein binding percentage was 29.5.