1. The disposition kinetics and plasma availability of danofloxacin in Muscovy ducks after single intravenous (i.v.), intramuscular (i.m.) and oral administrations of 5 mg/kg body weight were investigated. 2. Tissue residue profiles (liver, kidney and muscle) and plasma were also studied after multiple intramuscular and oral administration of 5 mg/kg once daily for 5 consecutive days. 3. The concentrations of the drug in the plasma and tissues were measured using high-performance liquid chromatography (HPLC) with fluorescence detection on samples collected at frequent intervals after drug administration. 4. Following intravenous injection, plasma concentration vs. time curves were best described by a two compartment open model. The decline in plasma drug concentration was bi-exponential with half-lives of (t(1/2alpha)) 0.08 h and (t(1/2beta)) 3.91 h for distribution and elimination phases, respectively. 5. After intramuscular and oral administration of danofloxacin at the same dose the peak plasma concentrations (C(max)) were 0.89 and 0.81 microg/ml and attained at 1.17 and 1.21 h (T(max)), respectively, and the elimination half-lives (T(1/2el)) were 2.91 and 2.39 h, respectively. The systemic bioavailabilities were 103.21 and 89.26%, following i.m. and oral admisistartion, respectively. In vitro protein binding percent of danofloxacin in Muscovy ducks plasma was 17%. 6. The tissue level following i.m. and oral administration were highest in liver and kidney, respectively, and decreased in the following order: plasma and muscle. No danofloxacin residues were detected in tissues and plasma after 96 h with either route of administration except in liver and kidney, after 120 h in case of oral administration.