The goal of this study was to measure the plasma concentrations of tiludronate in a population of race and sport horses under field conditions, and using pharmacokinetic population modeling, to estimate detection times for doping control. This study was conducted under field conditions on 39 race or sport horses diagnosed with bone conditions based on a lameness examination and treated with tiludronate. Each horse received 1 mg/kg of tiludronate (Tildren®) intravenously (i.v.).