title: Cytologic patterns of lymphadenopathy in canine monocytic ehrlichiosis.
abstract: BACKGROUND
  Recognition of different cytologic patterns in lymph nodes (LNs) from dogs with canine monocytic ehrlichiosis (CME) and noninfectious causes of lymphoid reactivity may have diagnostic utility.
  
  
  OBJECTIVE
  The aims of the present study were to compare cytologic patterns in LNs of dogs with different phases of CME, to investigate the association of cytologic pattern and presence of Ehrlichia spp. morulae, and to compare patterns of lymphoid reactivity between dogs with CME and those with noninfectious causes of lymphoid hyperplasia.
  
  
  METHODS
  Cytologic preparations of LNs from 35 dogs with nonmyelosuppressive CME (group A), 16 dogs with myelosuppressive CME (group B), 26 dogs with noninfectious diseases (group C), and 15 healthy dogs (group D) were evaluated. Percentages of lymphocyte types, plasma cells, macrophages, neutrophils, and eosinophils were determined. Samples from dogs in groups A and B were evaluated for the presence of morulae.
  
  
  RESULTS
  Cytologic abnormalities in LNs were recorded in 54% of dogs in group A, 88% in group B, 39% in group C, and 0% in group D and were more frequent (P=.02) in dogs with myelosuppressive CME than those with nonmyelosuppressive CME. Plasma cell hyperplasia was more frequent in CME than in noninfectious diseases (P=.03). An association between the presence of cytologic abnormalities and morulae in group A dogs was not found.
  
  
  CONCLUSIONS
  Dogs with myelosuppressive CME have more lymphoid cytologic abnormalities than dogs with nonmyelosuppressive CME. LN plasmacytosis is the major pattern of lymphadenopathy in dogs with CME and is found more frequently in dogs with CME than in dogs with noninfectious causes of lymphadenopathy.
authors.affiliation: Companion Animal Clinic, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece. mmylonak@vet.auth.gr
authors.forename: Mathios E
authors.initials: ME
authors.lastname: Mylonakis
authors.forename: Dori L
authors.initials: DL
authors.lastname: Borjesson
authors.forename: Leonidas
authors.initials: L
authors.lastname: Leontides
authors.forename: Victoria I
authors.initials: VI
authors.lastname: Siarkou
authors.forename: Konstantina
authors.initials: K
authors.lastname: Theodorou
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Koutinas
mesh_terms: D000818:Animals; D044963:Biopsy, Fine-Needle / Q000662:veterinary; D016022:Case-Control Studies; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D041061:Ehrlichia canis; D016873:Ehrlichiosis / Q000473:pathology / Q000662:veterinary*; D005260:Female; D008198:Lymph Nodes / Q000166:cytology / Q000473:pathology; D008206:Lymphatic Diseases / Q000473:pathology / Q000662:veterinary; D008214:Lymphocytes / Q000473:pathology; D008297:Male; D009000:Monocytes / Q000473:pathology; D010950:Plasma Cells / Q000473:pathology; D012189:Retrospective Studies