title: Acute toxicity of diphacinone in Northern bobwhite: effects on survival and blood clotting.
abstract: The anticoagulant rodenticide diphacinone was slightly toxic (acute oral LD50 2014 mg/kg) to Northern bobwhite (Colinus virginianus) in a 14-day acute toxicity trial. Precise and sensitive assays of blood clotting (prothrombin time, Russell's Viper venom time, and thrombin clotting time) were adapted for use in quail, and this combination of assays is recommended to measure the effects of anticoagulant rodenticides. A single oral sublethal dose of diphacinone (434 mg/kg body weight) prolonged clotting time at 48 h post-dose compared to controls. At 783 mg/kg (approximate LD02), clotting time was prolonged at both 24 and 48 h post-dose. Prolongation of in vitro clotting time reflects impaired coagulation complex activity, and was detected before overt signs of toxicity were apparent at the greatest dosages (2868 and 3666 mg/kg) in the acute toxicity trial. These clotting time assays and toxicity data will assist in the development of a pharmacodynamic model to predict toxicity, and also facilitate rodenticide hazard and risk assessments in avian species.
authors.affiliation: Patuxent Wildlife Research Center, U.S. Geological Survey, Department of the Interior, 10300 Baltimore Avenue, BARC East-308, Beltsville, MD 20705, USA. brattner@usgs.gov
authors.forename: Barnett A
authors.initials: BA
authors.lastname: Rattner
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Horak
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Warner
authors.forename: John J
authors.initials: JJ
authors.lastname: Johnston
mesh_terms: D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects*; D001780:Blood Coagulation Tests; D003088:Colinus / Q000097:blood / Q000254:growth & development; D004305:Dose-Response Relationship, Drug; D007928:Lethal Dose 50; D010630:Phenindione / Q000031:analogs & derivatives* / Q000633:toxicity; D018570:Risk Assessment; D012378:Rodenticides / Q000633:toxicity*; D023382:Toxicity Tests, Acute
chemical_list: D012378:Rodenticides; C100262:diphenadione; D010630:Phenindione