Pharmacokinetics of ceftiofur crystalline-free acid after single subcutaneous administration in the Attwater's prairie chicken (Tympanuchus cupido attwateri )

The use of antimicrobials is an important component of veterinary care provided to critically endangered Attwater's prairie chickens (Tympanuchus cupido attwateri) in captive breeding programs. Ceftiofur crystalline-free acid (CCFA) is a third-generation cephalosporin with broad-spectrum and long-acting properties approved for use in cattle, swine, and horses. The objective of this study was to determine the pharmacokinetic parameters of CCFA after a single-dose administration to apparently healthy adult Attwater's prairie chickens. A dose of 20 mg/kg was administered SC to six birds, and blood samples were collected at 4, 8, 12, 24, 48, 72, 96, and 120 h after drug administration. Plasma concentrations of ceftiofur equivalents were measured by liquid chromatography-tandem mass spectrometry. CCFA was absorbed rapidly, and plasma drug concentrations were maintained above the minimum inhibitory concentration previously determined for common bacterial organisms in avian species (≤ 1 µg/ml), through the end of the data collection period (120 h) in all birds. No signs of adverse drug reactions were observed in any birds during the study. On the basis of these results, an SC injection of CCFA at 20 mg/kg appears to be a promising, long-acting antimicrobial for use in Attwater's prairie chickens. Additional studies are needed to evaluate the pharmacokinetics, efficacy, and safety of repeat dosing.