Each of the four monocytes shown here as examples are from different species but all could be found in blood of any individual animal of any species. For example, the canine monocyte shown here would feel equally at home in a smear of horse blood and the cat monocyte could have been in dog blood. Note how the canine lymphocyte mimics a toxic band neutrophil (but there is less heterochromatin or less clumped chromatin and a more uniform cytoplasm color than would be expected from a toxic band neutrophil which would have more clumped chromatin and streaky blue or irregular blue cytoplasm with cytoplasmic basophilia). Vacuoles are seen in some but not all monocytes and is not a species-dependent change.
