Pharmacokinetic indices for cefovecin after single‐dose administration to adult sea otters ( Enhydra lutris )

Seven sea otters received a single subcutaneous dose of cefovecin at 8 mg/kg body weight. Plasma samples were collected at predetermined time points and assayed for total cefovecin concentrations using ultra‐performance liquid chromatography and tandem mass spectrometry. The mean (± SD ) noncompartmental pharmacokinetic indices were as follows: C Max (obs) 70.6 ± 14.6 μg/ mL , T Max (obs) 2.9 ± 1.5 h, elimination rate constant ( k el ) 0.017 ± 0.002/h, elimination half‐life ( t 1/2 k el) 41.6 ± 4.7 h, area under the plasma concentration‐vs.‐time curve to last sample ( AUC last) 3438.7 ± 437.7 h·μg/ mL and AUC extrapolated to infinity ( AUC 0→∞ ) 3447.8 ± 439.0 h·μg/mL. The minimum inhibitory concentrations ( MIC ) for select isolates were determined and used to suggest possible dosing intervals of 10 days, 5 days, and 2.5 days for gram‐positive, gram‐negative, and Vibrio parahaemolyticus bacterial species, respectively. This study found a single subcutaneous dose of cefovecin sodium in sea otters to be clinically safe and a viable option for long‐acting antimicrobial therapy.