Wright's stain, 500x

Ehrlichia sp. is a rickettsial organism capable of infecting many domestic species. The morula of this organism can be found in certain leukocytes, as well as in platelets when  the infection is due to Ehrlichia platys. These micro-organisms are transmissible by ticks. Despite the fact that this organism can be found on blood smears or in cytologic specimens, a serological test is usually required for diagnosis. The morula of Ehrlichia sp.looks like a small cluster of grapes. It is composed of elementary bodies and found in the cytoplasm of leukocytes.