title: Outbreaks of pleuritis and peritonitis in calves associated with Pasteurella multocida capsular type B strain.
abstract: METHODS
  Three dairy calf-rearing properties experienced high mortality in calves during 2008 and 2009. Affected calves were aged 13-18 weeks (Farm I), 6 months (Farm II), and 2-11 weeks (Farm III), and the mortality rate was 22/175 (13%), 5/80 (6%), and 60/900 (7%), respectively.
  
  
  RESULTS
  Affected calves rapidly became moribund, were in respiratory distress, and had a fever (40-41°C). Post-mortem examination of nine calves revealed fibrinopurulent pleuritis, pericarditis, and peritonitis. This was confirmed histopathologically on tissues from three calves, one from each farm; aggregates of small Gram-negative coccobacilli were evident on Gram stain. Pasteurella multocida was cultured from tissues from affected calves on the three farms, and PCR of DNA extracted from tissue samples amplified cap-sular type B-specific DNA. Multi-locus sequence typing (MLST) demonstrated that all capsular type B isolates belonged to the same sequence type (ST), ST62, but did not belong to serotype B:2, the only B serotype classified as causing haemorrhagic septicaemia by the Office International des Epizooties (OIE).
  
  
  METHODS
  Pleuritis and peritonitis due to infection with P. multocida capsular type B strain.
  
  
  CONCLUSIONS
  Haemorrhagic septicaemia was excluded as a cause of disease from the three farms, however P. multocida was the primary agent in the affected calves. It is possible the agent has been present in New Zealand for some time but not reported, as there had been no transfer of animals between affected farms. Emergence of the syndrome could potentially be a result of factors other than just the presence of the organism, such as changing management. The syndrome described may be of increasing importance in the future.
authors.affiliation: Investigation and Diagnostic Centre, Wallaceville, Biosecurity New Zealand, Ministry of Agriculture and Forestry, Upper Hutt 5018, New Zealand. andrew.mcfadden@maf.govt.nz
authors.forename: A M J
authors.initials: AM
authors.lastname: McFadden
authors.forename: H
authors.initials: H
authors.lastname: Christensen
authors.forename: R A
authors.initials: RA
authors.lastname: Fairley
authors.forename: F I
authors.initials: FI
authors.lastname: Hill
authors.forename: J M
authors.initials: JM
authors.lastname: Gill
authors.forename: S E
authors.initials: SE
authors.lastname: Keeling
authors.forename: R P
authors.initials: RP
authors.lastname: Spence
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology*; D004196:Disease Outbreaks / Q000662:veterinary*; D005260:Female; D008297:Male; D009520:New Zealand / Q000453:epidemiology; D010326:Pasteurella Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D016979:Pasteurella multocida / Q000145:classification*; D010538:Peritonitis / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D010998:Pleurisy / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*