Clinical Haematology 2

Question 1

What causes reduced RBC mass in anaemia?

Answer 1

Reduced RBC

Reduced haemoglobin concentration

Reduced PCV and haematocrit

Question 2

What are the classifications of anaemia?

Answer 2

RBC indexes:
Macrocytic / normocytic / microcytic
Normochromic / hypochromic

Regenerative vs non-regenerative

Severity of anaemia - how low the haematocrit is

Question 3

Define normocytic anaemia.

Answer 3

Erythrocytes of normal size.

Question 4

Define microcytic anaemia.

Answer 4

Low MCV - iron deficiency allows one more division of RBCs

Smaller RBCs

Question 5

Define macrocytic anaemia.

Answer 5

High MCV - presence of immature RBCs (larger than mature RBCs)

Common artefact in stored/old blood samples.

Question 6

Define hypochromic anaemia.

Answer 6

Low MCHC/MCH - iron deficiency leads to presence of immature RBCs (not fully haemoglobinised)

Question 7

Define hyperchromic anaemia.

Answer 7

High MCHC/MCH

Usually an artefact.

Question 8

What are the types of reticulocytes present in cats?

Answer 8

Aggregate - immature, look like canine reticulocytes, released by bone marrow in response to anaemia. Mature to punctate after 12-24 hours in circulation.

Punctate - scattered dots of reticulum, undergone a degree of maturation, can remain in bloodstream for up to 4 weeks after anaemia has resolved.

Question 9

What is anisocytosis?

Answer 9

Cells of different sizes - macrocytosis / microcytosis / polychromasia?

Question 10

What is polychromasia?

Answer 10

Purple RBCs, indicative of regeneration.

Question 11

What is hypochromasia?

Answer 11

Lack of haemoglobin = pale cells (bigger than 1/3rd of cell).

Described as “bicycle wheels”.

Usually seen alongside microcytosis in iron deficiency anaemia.

Question 12

What are spherocytes and ghost cells?

Answer 12

Spherocytes = perfectly round with no central pallor.

Ghost cells = just membrane with no content.

Both seen with IMHA.

Spherocytes also seen in low numbers with evidence of shear damage injury.

Question 13

What is polycythaemia?

Answer 13

Increased red cell mass, evidenced in increased haemoglobin / PCV / HCT / RBC.

Question 14

What is the difference between relative and absolute polycythaemia?

Answer 14

Relative = due to loss of plasma volume/dehydration (erythrocytosis)

Absolute = where red cell mass is increased (true polycythaemia)

Question 15

What is thrombocytopenia?

Answer 15

Low platelet numbers.

Spontaneous haemorrhage can occur at very low counts (<50 x10 9/L)

Question 16

What is a WBC differential count and how is it carried out?

Answer 16

Calculates %s of different leukocyte types.

x40/50 lens, count 100 cells per 10x10 9/L WBC count, % converted to absolute numbers (x10 9/L) using total WBC count.

Question 17

What is the appearance of a band neutrophil?

Answer 17

U or S shaped nucleus with parallel sides (minimal indentation/segmentation).

Question 18

What is lymphocytosis and what does it mean in young animals?

Answer 18

Increased lymphocyte count.

Young animals do not have true lymphocytosis, it is age-appropriate.