Isolation in Illinois of a foreign strain of Ehrlichia canis, the causative agent of canine ehrlichiosis (tropical canine pancytopenia)

Abstract

Ehrlichiosis (tropical canine pancytopenia) was diagnosed in Illinois in a 4.5 yr old mixed breed dog that had spent the previous 2 yr in India. The dog had periodic epistaxis, anemia, leukopenia, hypoalbuminemia, and hypergammaglobulinemia. A titer of 1:160 for Ehrlichia canis was detected by the indirect fluorescent antibody test. Subinoculation of blood into a clinically normal dog resulted in typical signs of canine ehrlichiosis, and E canis was identified in circulating mononuclear cells. The recipient died 23 days after inoculation, and typical gross and microscopic lesions of ehrlichiosis were found at necropsy. Ecchymoses and petechiae were found on the gallbladder, kidneys, small intestinal mucosa, cerebrum, and cerebellum. Plasmacytosis and perivascular cuffing were evident in various organs, especially the cerebrum, cerebellum, and meninges.