Efficacy of a Doxycycline Treatment Regimen Initiated during Three Different Phases of Experimental Ehrlichiosis

• DOI: 10.1128/aac.01622-09
• Publication Date: 2010-10-05T04:24:45Z
• Authors: Jennifer C. McClure; Michelle L. Crothers; John J. Schaefer; Patrick D. Stanley; Glen R. Needham; S. A. Ewing; Roger W. Stich
• Keywords: Ehrlichia canis; Rhipicephalus sanguineus; Ehrlichiosis; Subclinical infection; Regimen; Xenodiagnosis; Tick-borne disease; Babesia canis

Doxycycline is the treatment of choice for canine monocytic ehrlichiosis (CME), a well-characterized disease and valuable model tick-borne zoonoses. Conflicting reports clearance Ehrlichia canis after with doxycycline suggested that phase during which initiated influences outcomes these treatments. The purpose this study was to evaluate efficacy 28-day regimen experimental E. infections from dogs treated three phases disease. Ten were inoculated blood carriers acute, subclinical, or chronic CME. Daily rectal temperatures semiweekly samples monitored each dog, Rhipicephalus sanguineus ticks acquisition fed on dog xenodiagnosis. Blood collected acute subclinical CME became PCR negative as clinical parameters improved, but remained intermittently positive. R. treatments positive canis, regardless when initiated. However, fewer feeding two persistently infected followed by rifampin, suggesting antibiotic therapy can reduce tick canis.