Blood Smear Morphology Reference for Dogs and Cats
Reference for classic RBC, WBC, and platelet morphology findings on a blood smear. Filter by cell line or search a finding to see its appearance and clinical significance.
This reference describes classic morphologic patterns to guide slide review.
A full diagnosis requires a complete clinical picture and often a board-certified clinical pathologist's review, especially for borderline or unusual findings.
Cell line
Frequently asked questions
Why are spherocytes more useful for diagnosing IMHA in dogs than in cats?
Feline RBCs normally lack the central pallor that spherocytes are identified by its absence of, making spherocytes much harder to reliably recognize on a feline blood smear compared to a canine one.
What causes echinocytes (burr cells) most commonly?
Most often it's a sample-handling or EDTA-storage artifact rather than true disease - but persistent echinocytes on a fresh, well-made smear can reflect envenomation, electrolyte disturbances, or renal disease.
Why does platelet clumping matter on a blood smear?
Clumped platelets aren't counted individually by automated analyzers, causing a falsely low platelet count - always confirm true thrombocytopenia by scanning the smear's feathered edge for clumps before treating a low automated count as real.
What does a "left shift" on a CBC indicate?
An increase in immature band neutrophils being released from the bone marrow reserve, indicating the body is responding to an acute inflammatory or infectious demand for neutrophils beyond what the mature circulating pool can supply.