What angle should you hold the slide for a blood smear?
What is counted in a blood smear differential?
Segmented Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils, and sometimes bands
What should be noted about the RBC’s?
Cell size, hemoglobin content, morphology, and distribution
What should be noted about platelets?
Morphology and estimate number
In how many field should you look at RBC’s and Platelets?
Canine Erythrocyte Characteristics-
Generally largest RBC’s
Very uniformed RBC’s
More Central pallor in RBC’s
Variation in platelet size
Rouleaux is unusual
Feline Erythrocyte Characteristics-
Smaller RBC than Dog
Less Central PallorMore chance for Rouleaux and anisocytosis
Bovine Erythrocyte Characteristics-
RBC’s similar to cats in size, uniformity, and pallor
Rouleaux is not typical
Lymphocytes out number Neutrophils
Platelets are smaller and very granular
Equine Erythrocyte Characteristics-
RBC’s similar to cats in size and uniformity
Platelets have faint color and uniformed size
Cool basophils and eosinophils
Lots of Rouleaux
Avian Erythrocyte Characteristics-
RBC’s similar to cats in size and pallor
Oval nucleated RBC’s
Rouleaux is not typical
Platelets are small and granular
Camelids Erythrocyte Characteristics-
boring, oval, and uniformed
Variation in SHAPE to RBC’s
Poikilocytes is a general term for -
Acanthocytes, Schistocytes, Spherocytes, Target Cells, and others
RBC’s with increased membrane or decreased volume (Target Cells and Folded Cells)
Variation in SIZE of RBC’s
smaller than normal RBC; may indicate Chronic blood loss
Larger than normal RBC; may be young cell, may indicate response to certain anemias
As cells mature, what happens to the size of them?
They get smaller
AKA= Reticulocytes=immature RBC’s, larger than mature RBC’s, blue staining granular material (RNA) in cytoplasm, Response to regenerative anemia
Polychromatophils/ Immature RBC’s main to response to what?
AKA= Burr Cells, Response to renal failure, snake bits, lymphosarcoma, heavy activity in equine. Called crenation if artifact
What is an echinocyte called if it is an artifact?
AKA= Spur Cells, altered lipid metabolism, liver disease(ex. Hepatic lipidosis in cats), most commonly seen in Hemangiosarcoma
lack of Central Pallor, smaller than normal, reduced membrane, macrophage destruction, more likely seen in dogs, Immune mediated disease, hemolytic anemia, transfution w/ rejection
AKA= Codocytes, specific Leptocytes, May also indicate liver disease, chronic anemia, non-regenerative anemia…
normal up to 5% in cats, hyperthyroidism, Lymphosarcoma, stains blue w/ new methylene staining, Excess #’s due to toxicity like Tylenol, garlic, or onion
Howell Jolly Bodies-
nuclear remnant in RBC, normally cleared by spleen, splenectomized patients show increase, anemia
dead cell which outline remains visible but nucleus and cytoplasmic structure are not stainable
irregular shape appears as a helmet, indicative of a microangiopathic hemolytic anemia (MAHA) or other causes of hemolysis, Disseminated intravascular Coagulopathy (DIC)
organized stacking or chains of RBC’s, normal in equine, suggests inflammatory disease in other species
irregular/ misshapen clumps of RBC’s, indicative of mismatched transfusion or autoimmune
Normal is 2-4 segs, aged neutrophils, often seen in Chronic infections or anemia
Immature neutrophils, response to inflammation, ‘Left shift’
What is a ‘Left Shift’?
Increase in Bands
collection of rough endoplasmic reticulum, more prevalent in cats and horses from simple inflammation, indicates burns, bad infections, and chemotherapy/ often presents with basophilia, Left Shift, foaminess of cytoplasm