PRACTICAL: anaemia

Question 1

Why examine blood?

Answer 1

• RBCs (anaemia, erythrocytosis)
• WBCs (inflammation, neoplasia, chemo)
• PLTs (bleeding disorders, DIC)
• Plasma (colour

Question 2

Why use 4x magnification?

Answer 2

great for overview, less detail

Question 3

Why use 10x magnification?

Answer 3

good overview

good for scanning the feathered edge

Question 4

Why use 40x magnification?

Answer 4

• ‘high dry’ needs coverslip
• will only give sharp image with extra layer f glass
• drags into oil on slide (be careful)

Question 5

Why use 50x oil?

Answer 5

• great objective, expensive

- great for leukocyte differential

Question 6

Why use 100x oil?

Answer 6

• essential if 50x oil not available

- highest magnification - best to confirm organisms and fine structures

Question 7

What to look for on blood smear?

Answer 7

• EVEN DISTRIBUTION: leukocytes clumping, PLT clumping, agglutination
• FEATHERED EDGE: large things (cells, organsisms), mast cells
• MONOLARER: cell morphology, differentials, zig zagging
• ALL THREE COMPONENTS: platelets, RBCs, WBCs

Question 8

Is slight anisocytosis a normal finding?

Answer 8

• Yes - cats

- No - dogs

Question 9

Signs of regenerative anaemia

Answer 9

• anisocytosis
• polychromasia (subtle differences in staining)
• larger, blue-purple cells are polychromatophils
• reticulocytes with very dark precipitated RNA (reticulin) in faintly staining cytoplasm

Question 10

What causes Heinz bodies?

Answer 10

oxidative damage to Hg

Question 11

What are prekeratocytes?

Answer 11

• shear injury damage to RBCs
• they are erythrocytes with a clear vacuole towards the rim of the cell
• if this vacuole breaks open a keratocyte (helmet cell) is formed).
• microangiopathic (small BV) damage as in tumours is a common cause

Question 12

Name 4 examples of shear injury damage

Answer 12

• prekaryocytes
• keratocytes
• schistocytes
• acanthocytes

Question 13

What are spherocytes?

Answer 13

• erythrocytes with a smaller than average diameter d/t their spherical shape
• lack of central pallor
• IMHA hallmark

Question 14

What are acanthocytes?

Answer 14

• unvenly spaced, long blunt porjection on the RBC surface

- can be d/t HSA in GSD

Question 15

Appearance - iron deficiency anaemia

Answer 15

• lighter appearance to erythrocytes
• many leptocytes (very thin RBCs)
• increased central pallor
• increased # platelets (not uncommon in Fe deficiency)

Question 16

Appearance - Babesia

Answer 16

• within erythrocytes

- single, pairs or possibly 4 oval to teardrop shaped, lightly blue organisms