Pharmacokinetics of cefovecin sodium after subcutaneous administration to Hermann's tortoises (Testudo hermanni).

Abstract

To determine the pharmacokinetics of cefovecin sodium after SC administration to Hermann's tortoises (Testudo hermanni). 23 healthy adult Hermann's tortoises (15 males and 8 females). Cefovecin (8.0 mg/kg) was injected once in the subcutis of the neck region of Hermann's tortoises, and blood samples were obtained at predetermined time points. Plasma cefovecin concentrations were measured via ultraperformance liquid chromatography coupled to tandem mass spectrometry, and pharmacokinetic parameters were calculated with a noncompartmental model. Plasma protein concentration was quantified, and the percentage of cefovecin bound to protein was estimated with a centrifugation technique. Cefovecin was absorbed rapidly, reaching maximum plasma concentrations between 35 minutes and 2 hours after administration, with the exception of 1 group, in which it was reached after 4 hours. The mean ± SD time to maximum concentration was 1.22 ± 1.14 hours; area under the concentration-time curve was 220.35 ± 36.18 h•μg/mL The mean protein-bound fraction of cefovecin ranged from 41.3% to 47.5%. No adverse effects were observed. Administration of a single dose of cefovecin SC appeared to be well-tolerated in this population of tortoises. Results of pharmacokinetic analysis indicated that the 2-week dosing interval suggested for dogs and cats cannot be considered effective in tortoises; however, further research is needed to determine therapeutic concentrations of the drug and appropriate dose ranges.