Wildlife contamination with fluoroquinolones from livestock: Widespread occurrence of enrofloxacin and marbofloxacin in vultures

Abstract

There is much recent interest in the presence and impact of veterinary pharmaceuticals in wildlife. Live- stock carcasses are often disposed of in supplementary feeding stations for avian scavengers, as a man- agement and conservation tool for these species worldwide. In feeding stations, vultures and other scav- engers can consume carcasses almost immediately after disposal, which implies the potential ingestion of veterinary pharmaceuticals as a non-target consequence of supplementary feeding. Using UPLC-MS/MS and HPLC-TOF, we evaluated the presence and concentration of fluoroquinolone residues in plasma of nestling vultures feeding on domestic livestock carrion. Three different fluoroquinolones (marbofloxacin, enrofloxacin and its metabolite ciprofloxacin) and a non-targeted ß-lactam (nafcillin) were detected in vulture plasma. The high proportion of individuals (92%) with fluoroquinolone residues at variable con- centrations (up to ~20 ¿g L¿1 of enrofloxacin and ~150 ¿g L¿1 of marbofloxacin) sampled in several ge- ographically distant colonies and on different dates suggests that these and other drugs were potentially ingested throughout nestling development. Contamination with veterinary fluoroquinolones and other pharmaceuticals should be considered as an unintended but alarming consequence of food management in threatened wildlife.