title: Quantitative and qualitative leukocyte abnormalities in dogs with experimental and naturally occurring acute canine monocytic ehrlichiosis.
abstract: BACKGROUND
  Canine monocytic ehrlichiosis (CME) is one of the most important tick-borne diseases worldwide. Cytopenias have been observed in both acute (nonmyelosuppressive) and chronic (myelosuppressive) CME; however, leukocyte abnormalities and indices have been incompletely described in dogs with acute CME.
  
  
  OBJECTIVE
  The aims of this study were to analyze temporal changes in differential leukocyte counts, leukocyte morphology, myeloperoxidase index (MPXI), and lobularity index (LI) in dogs with experimental and naturally occurring acute CME.
  
  
  METHODS
  Differential leukocyte counts and morphology were evaluated in archived blood smears from 13 Beagle dogs experimentally infected with Ehrlichia canis and evaluated weekly for 42 days postinfection (DPI); 20 dogs with naturally occurring acute CME also were evaluated. MPXI and LI were obtained from ADVIA reports. Wilcoxon tests were used to assess changes over time; leukogram results in natural cases were assessed in comparison with reference intervals.
  
  
  RESULTS
  In experimental dogs, significant decreases in neutrophil, monocyte, lymphocyte, and eosinophil counts, and a mild left shift occurred within 14 DPI. The MPXI decreased significantly between 14 and 21 DPI and remained low, while LI increased from 14 to 35 DPI. Lymphocyte counts rebounded at 21 DPI, normalizing total WBC counts. Neutrophil toxicity was seen rarely, but reactive lymphocytes were observed frequently. Dogs with natural infection had variable patterns of leukocyte changes.
  
  
  CONCLUSIONS
  Acute CME is associated with several discrete quantitative and qualitative leukogram changes indicative of concurrent inflammation, antigenic stimulation, and stress. Changes in MPXI and LI warrant further investigation in dogs with CME and other diseases.
authors.affiliation: Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.
authors.forename: Athena
authors.initials: A
authors.lastname: Gianopoulos
authors.affiliation: Department of Clinical Sciences, Clinic of Companion Animals, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Mathios E
authors.initials: ME
authors.lastname: Mylonakis
authors.affiliation: Department of Clinical Sciences, Clinic of Companion Animals, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Konstantina
authors.initials: K
authors.lastname: Theodorou
authors.affiliation: Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.
authors.forename: Mary M
authors.initials: MM
authors.lastname: Christopher
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000097:blood* / Q000382:microbiology / Q000473:pathology; D004285:Dogs; D041061:Ehrlichia canis; D016873:Ehrlichiosis / Q000097:blood / Q000662:veterinary*; D005260:Female; D007958:Leukocyte Count / Q000662:veterinary; D007962:Leukocytes / Q000201:enzymology / Q000473:pathology*; D008297:Male; D009195:Peroxidase / Q000097:blood
chemical_list: D009195:Peroxidase
keywords: Ehrlichia canis; MPXI; inflammation; leukogram; lobularity index