Demonstration of serum antiplatelet antibodies in experimental acute canine ehrlichiosis

This report presents evidence for the presence of antiplatelet antibodies in sera of dogs experimentally infected with Ehrlichia canis, during the acute phase of the disease. Six healthy adult male beagle dogs were inoculated intravenously with blood from a longstanding infected dog with the Israel strain 611 of E. canis. Thrombocytopenia and concurrent increase in mean platelet volume were the most consistent haematological signs of the disease. The dogs developed an antibody titre to E. canis from Day 15 postinoculation. All dogs were antiplatelet antibody negative before inoculation. Twenty-four days postinoculation with E. canis, when the platelet count was at its lowest, antibodies to platelets were demonstrated, in the sera of five of the six dogs.