Evaluation of neutrophil oxidative metabolism in canine monocytic ehrlichiosis.

Background: Canine monocytic ehrlichiosis (CME) is a tick-borne disease caused by Ehrlichia canis, a rickettsia that infects the monocytes of dogs. This infection can result in a chronic and life-threatening disease. Thrombocytopenia, mild anemia, and leukopenia are the most common hematologic findings in CME. Objective: To investigate the role of peripheral blood neutrophils in CME, an evaluation was conducted of their functional state during the acute phase of the disease in dogs experimentally infected by E canis. Methods: Seven dogs were inoculated with E canis, and 3 remained as uninfected controls. All dogs had physical exams and hematologic tests (CBC and nitroblue tetrazolium [NBT] reduction) during a 6-week period.  Results: There was no difference (P > .05) in spontaneous NBT reduction results between the 2 groups of dogs throughout the 6-week period of observation. Nevertheless, when stimulated, the neutrophils showed higher activity in the infected group (P= .01) on weeks 4 and 5 after infection. Conclusion: Infection by E canis has no influence on neutrophil oxidative metabolism even though during the remission period of the acute phase of the disease, the neutrophils seem to be more reactive under stimulation.