Avian Erythrocyte Morphology

Erythrocytic Polychromasia
Polychromasia refers to variation in erythrocyte coloration. This variation largely relates to the maturation of the cell. The younger form will appear with bluer cytoplasm in Romanowsky stains; the mature form will stain uniformly orange-pink. No standardized index of avian polychromasia is being employed clinically. A slight degree of polychromasia is normal. Increases in polychromasia suggest an increased bone marrow response. No polychromasia correlates with non-responsive, anemic patients, which is characterized by all cells exhibiting the same coloration. This finding presents a guarded prognosis, pending resolution of the cause of the non-regeneration.

Erythrocytic Anisocytosis
Mature avian erythrocytes are oval-shaped and nucleated. Less mature cells are rounder in shape and more basophilic in color. Reticulocytes are normally present in peripheral blood at approximately 1-2% of the total erythrocyte count..
Anisocytosis describes the degree of variability of cell size. Laboratories employ a variety of schemes to describe and quantitate the degree of anisocytosis.