title: Causes of pneumonia epizootics among bighorn sheep, Western United States, 2008-2010.
abstract: Epizootic pneumonia of bighorn sheep is a devastating disease of uncertain etiology. To help clarify the etiology, we used culture and culture-independent methods to compare the prevalence of the bacterial respiratory pathogens Mannheimia haemolytica, Bibersteinia trehalosi, Pasteurella multocida, and Mycoplasma ovipneumoniae in lung tissue from 44 bighorn sheep from herds affected by 8 outbreaks in the western United States. M. ovipneumoniae, the only agent detected at significantly higher prevalence in animals from outbreaks (95%) than in animals from unaffected healthy populations (0%), was the most consistently detected agent and the only agent that exhibited single strain types within each outbreak. The other respiratory pathogens were frequently but inconsistently detected, as were several obligate anaerobic bacterial species, all of which might represent secondary or opportunistic infections that could contribute to disease severity. These data provide evidence that M. ovipneumoniae plays a primary role in the etiology of epizootic pneumonia of bighorn sheep.
authors.affiliation: Washington Animal Disease Diagnostic Laboratory, PO Box 647034, Washington State University, Pullman, WA 99164-7034, USA. tbesser@vetmed.wsu.edu
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Besser
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Highland
authors.forename: Katherine
authors.initials: K
authors.lastname: Baker
authors.forename: E Frances
authors.initials: EF
authors.lastname: Cassirer
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Anderson
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Ramsey
authors.forename: Kristin
authors.initials: K
authors.lastname: Mansfield
authors.forename: Darren L
authors.initials: DL
authors.lastname: Bruning
authors.forename: Peregrine
authors.initials: P
authors.lastname: Wolff
authors.forename: Joshua B
authors.initials: JB
authors.lastname: Smith
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Jenks
mesh_terms: D000818:Animals; D004269:DNA, Bacterial / Q000737:chemistry; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D016978:Mannheimia haemolytica / Q000235:genetics; D008969:Molecular Sequence Data; D045802:Mycoplasma ovipneumoniae / Q000235:genetics; D016979:Pasteurella multocida / Q000235:genetics; D010802:Phylogeny; D018410:Pneumonia, Bacterial / Q000453:epidemiology / Q000209:etiology / Q000662:veterinary*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology / Q000382:microbiology*; D034581:Sheep, Bighorn / Q000382:microbiology*; D014481:United States / Q000453:epidemiology
chemical_list: D004269:DNA, Bacterial; D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S