1. Protozoa or Rickettsial bacteria found in tissue cells of a dog .......... Go to: 3, 4, & 5
2. Protozoa or Rickettsial bacteria found in the blood of a dog .......... Go to: 6 & 7

3. Flagellates of the amastigote form (round cell, kinetoblast near nucleus, a short rudimentary flagellum) found in cardiac muscle, esophageal muscle or fibroblast cells .......... Trypanosoma cruzi
4. Flagellates of the amastigote form (round cell, kinetoblast near nucleus, a short rudimentary flagellum) found in spleen cells or liver cells .......... Leishmania donovani
5. Rickettsial bacteria (dark staining inclusions) found in monocytoid cells .......... Ehrlichia canis

6. Hemosporozoans (amoeboid or tear-shaped) found inside red blood cells .......... Go to: 8 & 9
7. Rickettsial bacteria forming cocci to chains of bacteria on the surface of red blood cells ........ Haemobartonella canis

8. A relative large Babesia, with a twin tear-shape appearance .......... Babesia canis
9. A small Babesia, with an amoeboid appearance .......... Babesia gibsoni