title: Efficacy of rifampicin in the treatment of experimental acute canine monocytic ehrlichiosis.
abstract: OBJECTIVE
  To assess the efficacy of rifampicin in achieving clinical and haematological recovery and clearing infection in dogs with experimentally induced acute monocytic ehrlichiosis.
  
  
  METHODS
  Five Ehrlichia canis-infected Beagle dogs were treated with rifampicin (10 mg/kg/24 h orally for 3 weeks), nine E. canis-infected dogs received no treatment (infected untreated dogs) and two dogs served as uninfected controls. Clinical score, platelet counts, immunofluorescent antibody titres and PCR detection of E. canis-specific DNA in blood, bone marrow and spleen aspirates were evaluated on post-inoculation days 21 (start of rifampicin), 42 (end of rifampicin) and 98 (end of the study).
  
  
  RESULTS
  By day 21 post-inoculation, all infected dogs became clinically ill and thrombocytopenic, seroconverted and were PCR positive in at least one tissue. Clinical scores and antibody titres did not differ between the treated and infected untreated dogs throughout the study. The rifampicin-treated dogs experienced an earlier resolution of their thrombocytopenia (Kaplan-Meier survival plot, P=0.048), and the median platelet counts were significantly higher in the treated compared with the infected untreated dogs on post-inoculation days 42 (P=0.0233) and 98 (P=0.0195). At the end of the study, three treated and six untreated infected dogs remained PCR positive in one tissue each.
  
  
  CONCLUSIONS
  The rifampicin treatment regimen applied in this study hastened haematological recovery, but was inconsistent in eliminating the acute E. canis infection.
authors.affiliation: Companion Animal Clinic, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Konstantina
authors.initials: K
authors.lastname: Theodorou
authors.forename: Mathios E
authors.initials: ME
authors.lastname: Mylonakis
authors.forename: Victoria I
authors.initials: VI
authors.lastname: Siarkou
authors.forename: Leonidas
authors.initials: L
authors.lastname: Leontides
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Koutinas
authors.forename: Christos K
authors.initials: CK
authors.lastname: Koutinas
authors.forename: Maria
authors.initials: M
authors.lastname: Kritsepi-Konstantinou
authors.forename: George
authors.initials: G
authors.lastname: Batzias
authors.forename: Eugenia
authors.initials: E
authors.lastname: Flouraki
authors.forename: Osnat
authors.initials: O
authors.lastname: Eyal
authors.forename: Vassilios
authors.initials: V
authors.lastname: Kontos
authors.forename: Shimon
authors.initials: S
authors.lastname: Harrus
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D058491:Bacterial Load; D001769:Blood / Q000382:microbiology; D001853:Bone Marrow / Q000382:microbiology; D004195:Disease Models, Animal; D004283:Dog Diseases / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D004285:Dogs; D041061:Ehrlichia canis / Q000302:isolation & purification; D016873:Ehrlichiosis / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D005260:Female; D008297:Male; D012293:Rifampin / Q000008:administration & dosage*; D012720:Severity of Illness Index; D013154:Spleen / Q000382:microbiology; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D012293:Rifampin
keywords: Ehrlichia canis; dogs; therapy