title: Differential leukocyte counts determined in chicken blood using the Cell-Dyn 3500.
abstract: BACKGROUND
  Automated hematology instruments commonly are used for mammalian blood analysis, but there is a lack of accurate automated methods available for avian leukocyte analysis.
  
  
  OBJECTIVE
  The aim of this study was to validate differential leukocyte counts in blood from chickens using the Cell-Dyn 3500 hematology system and avian-specific software.
  
  
  METHODS
  Blood samples were collected in lithium-heparin tubes from 2 groups (n = 84 and n = 139) of laying hens. Manual 200-cell differential counts were done on routinely-stained blood smears, and manual total granulocyte counts (heterophils and eosinophils) were done using an eosinophil stain in a counting chamber. Automated differential counts were done using VET 2.3, a research and development version of avian-specific software for the Cell-Dyn 3500. Results were analyzed using Pearson's correlation and difference plots.
  
  
  RESULTS
  Automated granulocyte counts from the Cell-Dyn were in good agreement with manual granulocyte counts (r = 0.93 and 0.80 for the 2 study groups). No correlation was found between automated and manual lymphocyte counts. Correlation coefficients for monocyte counts were 0.70 and 0.43.
  
  
  CONCLUSIONS
  Automated leukocyte results from the Cell-Dyn using VET 2.3 software were not fully accurate. Total granulocyte counts may be of clinical usefulness, but results obtained for other parameters were unreliable.
authors.affiliation: Department of Clinical Chemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden. inger.lilliehook@bvf.slu.se
authors.forename: Inger
authors.initials: I
authors.lastname: Lilliehöök
authors.forename: Helena
authors.initials: H
authors.lastname: Wall
authors.forename: Ragnar
authors.initials: R
authors.lastname: Tauson
authors.forename: Harold
authors.initials: H
authors.lastname: Tvedten
mesh_terms: D000818:Animals; D001322:Autoanalysis / Q000295:instrumentation / Q000379:methods / Q000592:standards / Q000662:veterinary*; D002645:Chickens / Q000097:blood*; D005260:Female; D006098:Granulocytes / Q000166:cytology; D006405:Hematology / Q000295:instrumentation / Q000379:methods / Q000592:standards; D007958:Leukocyte Count / Q000295:instrumentation / Q000592:standards / Q000662:veterinary*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity