title: Factors associated with pleurisy in pigs: a case-control analysis of slaughter pig data for England and Wales.
abstract: A case-control investigation was undertaken to determine management and health related factors associated with pleurisy in slaughter pigs in England and Wales.
  
  
  METHODS
  The British Pig Executive Pig Health Scheme database of abattoir pathology was used to identify 121 case (>10% prevalence of pleurisy on 3 or more assessment dates in the preceding 24 months) and 121 control units (≤5% prevalence of pleurisy on 3 or more assessment dates in the preceding 24 months). Farm data were collected by postal questionnaire. Data from respondents (70 cases and 51 controls) were analysed using simple logistic regression models with Bonferroni corrections. Limited multivariate analyses were also performed to check the robustness of the overall conclusions.
  
  
  CONCLUSIONS
  Management factors associated with increased odds of pleurisy included no all-in all-out pig flow (OR 9.3, 95% confidence interval [CI]: 3.3-29), rearing of pigs with an age difference of >1 month in the same airspace (OR 6.5 [2.8-17]) and repeated mixing (OR 2.2 [1.4-3.8]) or moving (OR 2.2 [1.5-3.4]) of pigs during the rearing phase. Those associated with decreased odds of pleurisy included filling wean-to-finish or grower-to-finish systems with piglets from ≤3 sources (OR 0.18 [0.07-0.41]) compared to farrow-to-finish systems, cleaning and disinfecting of grower (ORs 0.28 [0.13-0.61] and 0.29 [0.13-0.61]) and finisher (ORs 0.24 [0.11-0.51] and 0.2 [0.09-0.44]) accommodation between groups, and extended down time of grower and finisher accommodation (OR 0.84 [0.75-0.93] and 0.86 [0.77-0.94] respectively for each additional day of downtime). This study demonstrated the value of national-level abattoir pathology data collection systems for case control analyses and generated guidance for on-farm interventions to help reduce the prevalence of pleurisy in slaughter pigs.
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Henrike C
authors.initials: HC
authors.lastname: Jäger
authors.forename: Trevelyan J
authors.initials: TJ
authors.lastname: McKinley
authors.forename: James L N
authors.initials: JL
authors.lastname: Wood
authors.forename: Gareth P
authors.initials: GP
authors.lastname: Pearce
authors.forename: Susanna
authors.initials: S
authors.lastname: Williamson
authors.forename: Benjamin
authors.initials: B
authors.lastname: Strugnell
authors.forename: Stanley
authors.initials: S
authors.lastname: Done
authors.forename: Henrike
authors.initials: H
authors.lastname: Habernoll
authors.forename: Andreas
authors.initials: A
authors.lastname: Palzer
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Tucker
mesh_terms: D000003:Abattoirs / Q000706:statistics & numerical data*; D000818:Animals; D016022:Case-Control Studies; D004194:Disease; D004739:England / Q000453:epidemiology; D005062:European Union; D006262:Health; D010998:Pleurisy / Q000453:epidemiology / Q000662:veterinary*; D015995:Prevalence; D012044:Regression Analysis; D012307:Risk Factors; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology*; D014852:Wales / Q000453:epidemiology; D014886:Weaning