Erythrocytes
Mammals: no nucleus, biconcave disk except Camelids (oval)
Other vertebrates: nucleated
Central pallor: most obvious in dogs; not obvious in cat, horse, cow, sheep, goat
Regenerative anemia (caused by blood loss or destruction)
Decreased PCV
Basophilic stippling in dogs and cats
Nucleated RBCs
Howell-Jolly bodies
Normal or increased MCV
Increased RDW
Reticulocyte concentration >60,000 cells/ul (not in horses)
Polychromasia (not in horses)
Immature RBCs
Macrocytosis
Decreased production/nonregenerative anemia (marrow dysfunction, secondary disorder)
Decreased PCV w/o polychromasia
Increased MCV (esp in horses)
Normal MCV (may be pre-regenerative following hemolytic event or blood loss)
Decreased reticulocytes
Lack of immature RBCs
Iron-deficient anemia
Decreased PCV
Hypochromasia in dogs esp; not in cats
*Microcytosis (normal in Asian dog breeds)
*Decreased MCV
Increased RDW
Keratocytosis
Schistocytosis
Hemolytic anemia
Decreased PCV
Heinz bodies
Lead poisoning
Basophilic stippling w/o anemia
Nucleated RBCs
Portocaval shunt
Microcytic RBCs
FeLV
Macrocytosis w/o polychromasia
Nucleated RBCs w/o polychromasia
Nonregenerative anemia
Very immature RBCs w/severe nonregenerative anemia
DIC
Schistocytosis
Thrombocytopenia
Hemangiosarcoma
Schistocytosis
Acanthocytosis
Regenerative anemia
Hepatic lipidosis in cats
Acanthocytosis
Renal disease in dogs
Echinocytosis
Rattlesnake envenomation
Type 3 echinocytosis
Immune-mediated hemolytic anemia in dogs
*Spherocytosis
*Agglutination persistent in saline
Falsely increased MCV
Falsely decreased red blood cell count
Confirm with Coombs or saline fragility test
Zinc toxicosis
Heinz-body anemia
Spherocytosis
Oxidative damage
Eccentrocytosis esp in dogs
*Heinz bodies (present in 1-2% RBCs in normal cats)
Glucose-6-dehydrogenase deficiency
Eccentrosytosis
Diabetes mellitus in cats
Heinz bodies
Lymphoma in cats
Heinz bodies
Hyperthyroidism
Heinz bodies
Nonfunctioning spleen
Nucleated RBCs
Supressed splenic function
Howell-Jolly bodies
High corticosteroids
Nucleated RBCs
RBC parasites
Spherocytosis due to IMHA
Hemobartonella felis in cats causing feline infectious anemia
Cytauxzoon felis in cats
Hemobartonella canis in dogs that have been splenectomized
Babesia canis, B. gibsoni in dogs causing severe IMHA
Eperythrozoon sp
Anaplasma sp
Multiple myeloma, gammopathy
Increased rouleaux formation
Increased plasma protein (fibrinogen, Ig)
Inherited defects
Stomatocytosis in Alaskan Malamutes, miniature schnauzers, Drentse partijhond (Dutch partridge dog)
Macrocytosis in poodles
Artifacts
Echinocytosis
Leptocytosis
Codocytosis
Aplastic anemia
Nonregenerative anemia
Decreased leukocyte count
Decreased platelets