The document provides guidance on evaluating a blood smear under the microscope. Key areas to examine include the feathered edge for platelet clumping and atypical cells, the monolayer for white blood cell and red blood cell morphology as well as platelet counting. Normal canine red blood cells are biconcave while feline red blood cells vary more in shape without consistent central pallor. Abnormal red blood cell findings include evidence of regeneration, spherocytes, crenation/echinocytes, acanthocytes, schistocytes, Heinz bodies, basophilic stippling and Howell-Jolly bodies. White blood cell morphology notes characteristics of neutrophils, band neutrophils, lymphocytes, monocytes, eosinophils

1. BLOOD SMEAR EVAL

2. FEATHERED EDGE
 Quick scan on low power through entire slide for adequate distribution of
cells
 Check for plt clumping & atypical cells at feathered edge. (if there is plt
clumping there is no need to try and count plt in the monolayer)

3. MONOLAYER
 Where the action is at: diff 40X morph 100X
 WBC morph, RBC morph, plt count (if no plt clumping at feathered edge)

4. NORMAL RBCS
 Canine-Biconcave with area of central pallor 7um
 Feline-no consistent central pallor, vary more in shape 6um

5. RBC MORPHOLOGY
 Evidence of regeneration
 Polychromatophils-anisocytosis
 nRBC (<4/100WBCs)

6. AUTOAGGLUTINATION

7. SPHEROCYTES
 Spherical, Loss normal bioconcave shape, no central pallor >5/HPF is
abnormal

8. CRENATION/ECCHINOCYTES
 Often shrinking artifact-abn lytes, uremia, rattlesnake envenoation.

9. ACANTHOCYTES
 Irregularly spaced membrane projections-abnormal accumulation of lipids in
RBC membrane-metabolic, HAS, dz of liver, spleen and kidney

10. SCHISTOCYTE
 Fragmented by mechanical injury. DIC, microvascular hemolysis, HAS,
heartworm dz. 1/ 3HPF is abnormal

11. HEINZ BODIES
 Accumulations of damaged Hg-acetaminophen toxicosis, acute onion and
zinc toxicity in dogs, DM, lymphoma in cats

12. BASOPHILIC STIPPLING
 Punctate aggregates of ribosomes-from highly regenerative anemia or lead
toxicosis

13. HOWELL-JOLLY BODIES
 Nuclear remnants-regenerative anemia or splenic disease

14. PLATELETS
 # per 10HPF X 15,000

15. WBC MORPHOLOGY
 Neutrophils-lobulated nucleus with pale to light pink/ purple cytoplasm

16. BAND NEUTROPHIL
 U or J shaped nucleus, constriction of band <1/2 width of remainder,
cytoplasm similar to mature neutrophils. <5% normal.

17. TOXIC CHANGES
 Presence of dohle bodies, cytoplasmic basophilia (cytoplasm is more blud-
purple), foamy cytoplasmic vacuolization (soap bubbles).

18. LYMPHOCYTES
 Densely staining round to oval nuclei with small amounts of cytoplasm.
Reactive (antigenic stimulation) darker cytoplasm, increased size.

19. MONOCYTES
 Lots of light to deep blue cytoplasm (darker then neut) with nuclei that is
not round. Quite variable in appearance. Often larger then neuts and
lymphs.

20. EOSINOPHILS
 In low numbers, slightly smaller then neuts with less lobulated nuclei,
contains prominent pink granules which are rod shaped in cats.

21. BASOPHILS
 Largest, very uncommon, nucleus is ribbon like (not segmented) often with
pink/ purple granules present.