title: Cluster of cases of massive hemorrhage associated with anticoagulant detection in race horses.
abstract: Five horses originating from 4 different California race tracks were submitted to the California Animal Health and Food Safety Laboratory for necropsy and diagnostic workup. The 5 horses had a history of sudden collapse and death during exercise. In all of them, massive hemoperitoneum and hemorrhages in other cavities or organs were observed. The liver from these 5 animals and from 27 horses that had been euthanized due to catastrophic leg injuries (controls) were subjected to a rodenticide anticoagulant screen. Traces of brodifacoum, diphacinone, or bromadiolone were detected in the 5 horses with massive bleeding (5/5), and no traces of rodenticides were detected in control horses (0/27). Other frequent causes of massive hemorrhages in horses were ruled out in 4 of the cases; one of the horses had a pelvic fracture. Although only traces of anticoagulants were found in the livers of these horses and the role of these substances in the massive bleeding remains uncertain, it is speculated that exercise-related increases in blood pressure may have reduced the threshold for toxicity of these anticoagulants.
authors.affiliation: California Animal Health and Food Safety Laboratory System, University of California-Davis, San Bernardino branch (Carvallo, Kinde, Nyaoke, Uzal), CADavis branch (Poppenga, Diab, Hill), CASchool of Veterinary Medicine, University of California-Davis, Davis, CA (Arthur).
authors.forename: Francisco R
authors.initials: FR
authors.lastname: Carvallo
authors.affiliation: California Animal Health and Food Safety Laboratory System, University of California-Davis, San Bernardino branch (Carvallo, Kinde, Nyaoke, Uzal), CADavis branch (Poppenga, Diab, Hill), CASchool of Veterinary Medicine, University of California-Davis, Davis, CA (Arthur).
authors.forename: Robert
authors.initials: R
authors.lastname: Poppenga
authors.affiliation: California Animal Health and Food Safety Laboratory System, University of California-Davis, San Bernardino branch (Carvallo, Kinde, Nyaoke, Uzal), CADavis branch (Poppenga, Diab, Hill), CASchool of Veterinary Medicine, University of California-Davis, Davis, CA (Arthur).
authors.forename: Hailu
authors.initials: H
authors.lastname: Kinde
authors.affiliation: California Animal Health and Food Safety Laboratory System, University of California-Davis, San Bernardino branch (Carvallo, Kinde, Nyaoke, Uzal), CADavis branch (Poppenga, Diab, Hill), CASchool of Veterinary Medicine, University of California-Davis, Davis, CA (Arthur).
authors.forename: Santiago S
authors.initials: SS
authors.lastname: Diab
authors.affiliation: California Animal Health and Food Safety Laboratory System, University of California-Davis, San Bernardino branch (Carvallo, Kinde, Nyaoke, Uzal), CADavis branch (Poppenga, Diab, Hill), CASchool of Veterinary Medicine, University of California-Davis, Davis, CA (Arthur).
authors.forename: Akinyi C
authors.initials: AC
authors.lastname: Nyaoke
authors.affiliation: California Animal Health and Food Safety Laboratory System, University of California-Davis, San Bernardino branch (Carvallo, Kinde, Nyaoke, Uzal), CADavis branch (Poppenga, Diab, Hill), CASchool of Veterinary Medicine, University of California-Davis, Davis, CA (Arthur).
authors.forename: Ashley E
authors.initials: AE
authors.lastname: Hill
authors.affiliation: California Animal Health and Food Safety Laboratory System, University of California-Davis, San Bernardino branch (Carvallo, Kinde, Nyaoke, Uzal), CADavis branch (Poppenga, Diab, Hill), CASchool of Veterinary Medicine, University of California-Davis, Davis, CA (Arthur).
authors.forename: Rick M
authors.initials: RM
authors.lastname: Arthur
authors.affiliation: California Animal Health and Food Safety Laboratory System, University of California-Davis, San Bernardino branch (Carvallo, Kinde, Nyaoke, Uzal), CADavis branch (Poppenga, Diab, Hill), CASchool of Veterinary Medicine, University of California-Davis, Davis, CA (Arthur) fuzal@cahfs.ucdavis.edu.
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Uzal
mesh_terms: D015110:4-Hydroxycoumarins / Q000633:toxicity; D000818:Animals; D000925:Anticoagulants / Q000633:toxicity*; D002140:California; D006465:Hemoperitoneum / Q000139:chemically induced / Q000662:veterinary; D006470:Hemorrhage / Q000139:chemically induced / Q000662:veterinary*; D006734:Horse Diseases / Q000139:chemically induced*; D006736:Horses; D008099:Liver / Q000737:chemistry; D008297:Male; D010630:Phenindione / Q000031:analogs & derivatives / Q000633:toxicity; D010805:Physical Conditioning, Animal; D012378:Rodenticides / Q000633:toxicity*
chemical_list: D015110:4-Hydroxycoumarins; D000925:Anticoagulants; D012378:Rodenticides; C100262:diphenadione; D010630:Phenindione; C013418:bromfenacoum; C021636:bromadiolone
keywords: Brodifacoum; bromadiolone; diphacinone; horses; rodenticides; warfarin