Date: 19 Apr 2013

Canine Erythrocyte Morphology: Observations of a New Pattern, the “Quatrefoil” Erythrocyte

* Final gross prices may vary according to local VAT.

Get Access


The “quatrefoil” erythrocyte pattern may be observed during erythrocyte morphology evaluation in canine complete blood counts (CBCs). “Quatrefoil” red blood cells (RBCs) have been documented in blood smears using both optical and scanning electron microscopy. In our examination of 3,958 CBCs, we found a prevalence of 3.89 % “quatrefoil” RBCs. These RBCs mostly occurred between the body and feathered edge of the blood smears. This pattern was not statistically related to the breed or sex, but to the age of the dog (older dogs; p < 0.0001). “Quatrefoil” RBCs are not significantly associated with other morphological erythrocyte changes. However, compared with populations of dogs without “quatrefoil” RBCs, dogs with this RBC pattern are significantly more likely to exhibit lower total leukocyte and neutrophil counts. Hypotheses describing the origin of “quatrefoil” RBCs include artifact effects, dacryocyte overlapping, and the effect of adhesion forces between two circulating RBCs in the blood stream (i.e., tank-trading and/or tumbling).