title: Serologic and bacteriologic culture prevalence of Corynebacterium pseudotuberculosis infection in goats and sheep and use of Bayesian analysis to determine value of assay results for prediction of future infection.
abstract: OBJECTIVE
  To determine the serologic and bacteriologic culture prevalence of Corynebacterium pseudotuberculosis infection in sheep and goats and the value of such assays for prediction of future development of caseous lymphadenitis (CL).
  
  
  METHODS
  Observational study.
  
  
  METHODS
  919 goats and sheep in 3 herds in southwest Texas.
  
  
  METHODS
  During an initial evaluation, serologic and bacteriologic culture status for CL was determined for all animals. Subsequently, animals were evaluated every 6 months for a 13-month period to detect external CL lesions. Affected animals in 2 herds were treated with tulathromycin or a control treatment; affected animals in 1 herd were culled. The value of assays for prediction of future development of CL lesions was determined.
  
  
  RESULTS
  The serologic prevalence of CL in herds at the start of the study ranged from 7.52% to 69.54%. The bacteriologic culture prevalence of CL ranged from 0% to 6.12% at the start of the study and 0% to 9.56% at the end of the study. Synergistic hemolysin inhibition results were poor predictors of future development of CL lesions in animals during the study period; however, animals with positive bacteriologic culture results for CL were more likely to develop lesions in the future than were animals with negative bacteriologic culture results.
  
  
  CONCLUSIONS
  Caseous lymphadenitis was detected in animals in this study despite prior management of affected animals in herds via culling. Use of a synergistic hemolysin inhibition test for management of CL may cause unnecessary culling of animals; treatment might allow retention of genetically valuable CL-affected animals in a herd without substantially increasing the prevalence of CL.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Texas A&M University, College Station, TX 77843, USA. kwashburn@cvm.tamu.edu
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Washburn
authors.forename: Wesley T
authors.initials: WT
authors.lastname: Bissett
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Waldron
authors.forename: Virginia R
authors.initials: VR
authors.lastname: Fajt
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D003354:Corynebacterium Infections / Q000175:diagnosis / Q000662:veterinary*; D016925:Corynebacterium pseudotuberculosis; D015511:Goat Diseases / Q000097:blood* / Q000175:diagnosis / Q000382:microbiology; D006041:Goats; D011237:Predictive Value of Tests; D012698:Serologic Tests / Q000662:veterinary*; D012756:Sheep; D012757:Sheep Diseases / Q000097:blood* / Q000175:diagnosis / Q000382:microbiology