title: Desert bighorn sheep mortality due to presumptive type C botulism in California.
abstract: During a routine telemetry flight of the Mojave Desert (California, USA) in August 1995, mortality signals were detected from two of 12 radio-collared female desert bighorn sheep (Ovis canadensis) in the vicinity of Old Dad Peak in San Bernardino County (California). A series of field investigations determined that at least 45 bighorn sheep had died near two artificial water catchments (guzzlers), including 13 bighorn sheep which had presumably drowned in a guzzler tank. Samples from water contaminated by decomposing bighorn sheep carcasses and hemolyzed blood from a fresh bighorn sheep carcass were tested for the presence of pesticides, heavy metals, strychnine, blue-green algae, Clostridium botulinum toxin, ethylene glycol, nitrates, nitrites, sodium, and salts. Mouse bioassay and enzyme-linked immunosorbent assay detected type C botulinum toxin in the hemolyzed blood and in fly larvae and pupae. This, coupled with negative results from other analyses, led us to conclude that type C botulinum poisoning was most likely responsible for the mortality of bighorn sheep outside the guzzler tank.
authors.affiliation: California Department of Fish and Game, Wildlife Investigations Laboratory, Rancho Cordova 95670, USA. pswift@q.dfg.ca.gov
authors.forename: P K
authors.initials: PK
authors.lastname: Swift
authors.forename: J D
authors.initials: JD
authors.lastname: Wehausen
authors.forename: H B
authors.initials: HB
authors.lastname: Ernest
authors.forename: R S
authors.initials: RS
authors.lastname: Singer
authors.forename: A M
authors.initials: AM
authors.lastname: Pauli
authors.forename: H
authors.initials: H
authors.lastname: Kinde
authors.forename: T E
authors.initials: TE
authors.lastname: Rocke
authors.forename: V C
authors.initials: VC
authors.lastname: Bleich
mesh_terms: D000818:Animals; D000835:Animals, Wild; D001681:Biological Assay / Q000662:veterinary; D001905:Botulinum Toxins / Q000032:analysis*; D001906:Botulism / Q000175:diagnosis / Q000401:mortality / Q000662:veterinary*; D002140:California / Q000453:epidemiology; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000662:veterinary; D008297:Male; D051379:Mice; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis / Q000401:mortality*; D013686:Telemetry / Q000662:veterinary; D014881:Water Supply / Q000032:analysis*
chemical_list: D001905:Botulinum Toxins; C096324:botulinum toxin type C