Pharmacokinetics of intravenous and subcutaneous cefovecin in alpacas

The purpose of this study was to determine the pharmacokinetics of cefovecin after intravenous and subcutaneous dose of 8 mg/kg to alpacas. Bacterial infections requiring long-term antibiotic therapy such as neonatal bacteremia, pneumonia, peritonitis, dental, and uterine infections are a significant cause of morbidity and mortality in this species. However, few antimicrobials have been evaluated and proven to have favorable pharmacokinetics for therapeutic use. Most antimicrobials that are currently used require daily injections for many days. Cefovecin is a long-acting cephalosporin that is formulated for subcutaneous administration, and its long-elimination half-life allows for 14-day dosing intervals in dogs and cats. The properties of cefovecin may be advantageous for medical treatment of camelids due to its broad spectrum, route of administration, and long duration of activity. Pharmacokinetic evaluation of antimicrobial drugs in camelids is essential for the proper treatment and prevention of bacterial disease, and to minimize development of antibiotic resistant bacterial strains due to inadequate antibiotic concentrations. Cefovecin mean half-life, volume of distribution at steady-state, and clearance after intravenous administration were 10.3 h, 86 mL/kg, and 7.07 mL·h/kg. The bioavailability was 143%, while half-life, C(max), and T(max) were 16.9 h, 108 μg/mL, and 2.8 h following subcutaneous administration. In the absence of additional microbial susceptibility data for alpaca pathogens, the current cefovecin dosage regimen prescribed for dogs (8 mg/kg SC every 14 days) may need to be optimized for the treatment of infections in this species.