title: Coronavirus infection in intensively managed cattle with respiratory disease.
abstract: BACKGROUND
  A detailed laboratory investigation identified bovine coronavirus (BCoV) as the aetiological agent in an outbreak of respiratory disease at a semi-intensive beef cattle feedlot in south-east Australia. The outbreak caused 30% morbidity in the resident population and also affected two cohorts of cattle that were newly introduced to the property.
  
  
  METHODS
  At slaughter, pulmonary consolidation and inflammatory lesions in the trachea were identified in 15 of 49 animals. Pasteurella multocida or Histophilus somni was cultured from 3 of 7 animals with lesions. Histopathological examination revealed multifocal non-suppurative bronchointerstitial pneumonia with formation of epithelial syncytial cells, sometimes associated with suppurative bronchopneumonia.
  
  
  RESULTS
  BCoV was detected in nasal swabs and pulmonary lesions using real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) assay and virus isolation. There was serological evidence of previous exposure to bovine viral diarrhoea virus, bovine respiratory syncytial virus and bovine parainfluenza virus type 3, but not to bovine herpesvirus type 1. None of these viral pathogens or Mycoplasma bovis was identified by qRT-PCR.
  
  
  CONCLUSIONS
  This is believed to be the first report of BCoV in association with bovine respiratory disease complex in Australia.
authors.affiliation: Elizabeth Macarthur Agriculture Institute, Woodbridge Road, Menangle, New South Wales 2568, Australia.
authors.forename: P M
authors.initials: PM
authors.lastname: Hick
authors.forename: A J
authors.initials: AJ
authors.lastname: Read
authors.forename: I
authors.initials: I
authors.lastname: Lugton
authors.forename: F
authors.initials: F
authors.lastname: Busfield
authors.forename: K E
authors.initials: KE
authors.lastname: Dawood
authors.forename: L
authors.initials: L
authors.lastname: Gabor
authors.forename: M
authors.initials: M
authors.lastname: Hornitzky
authors.forename: P D
authors.initials: PD
authors.lastname: Kirkland
mesh_terms: D000822:Animal Husbandry / Q000379:methods; D000818:Animals; D001315:Australia / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D018352:Coronavirus Infections / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D017938:Coronavirus, Bovine / Q000302:isolation & purification*; D004196:Disease Outbreaks / Q000662:veterinary; D009296:Nasal Cavity / Q000821:virology; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary