Laboratory Diagnostic Aids

Question 1

What is polychromasia ?

Answer 1

Differing intensity of staining

Question 2

What is crenation?

Answer 2

Cells showing spiky margins due to shrinkage. Air drying of blood film too slow.

Question 3

What are Howell Jolly bodies?

Answer 3

These are basophilic nuclear remnants seen in erythrocytes. Due to anaemia and splenic disorders.

Question 4

What is Roleaux formation?

Answer 4

Arrangement of red blood cells into stacks. Associated with fibrinogen or globulin increase in blood. Normal in horses but not cats or dogs.

Question 5

What are reticulocytes?

Answer 5

Immature red blood cells with nucleus. IMHA, blood loss.

Question 6

What is anisocytosis?

Answer 6

Different size rbcs. Anaemia is cause.

Question 7

What increases PCV

Answer 7

Dehydration, diabetes insipidus.

Question 8

What decreases PCV

Answer 8

Anaemia, bleeding, hypovolaemic shock

Question 9

What causes Eosinophilia

Answer 9

Parasitic infestation

Allergy

Question 10

What causes eosinopenia

Answer 10

Steroid usage

Cushings disease

Question 11

What causes neutrophilia

Answer 11

Inflammation, infection, stress, steroids

Question 12

What is hemolysis

Answer 12

Disintegration of the red blood cells due to trauma, contact with certain chemicals or osmotic changes.

Question 13

Causes of hemolysis?

Answer 13

Too small needle used
Shaking of sample
Pulling on the syringe plunger too hard
Blood in contact with acid, alkali or alcohol

Question 14

Effects of hemolysis on a blood sample

Answer 14

Abnormally low rbc and pcv

abnormally high protein level

Question 15

What is lipaemia

Answer 15

Presence of lipids in the blood.

Usually from a feed prior to venepuncture.

Question 16

Effects of lipaemia on blood sample

Answer 16

Elevated biochem values

increased likelihood of haemolysis

Question 17

Serum vs plasma

Answer 17

Plasma contains clotting factor fibrinogen

Question 18

What is PCV

Answer 18

Packed Cell Volume - percentage of red blood cells in the blood. Also referred as haematocrit.

Question 19

What is normal dog and cat pcv

Answer 19

Dog 37-55%

Cat 30-45%

Question 20

Why is EDTA used for PCV ?

Answer 20

EDTA removes calcium needed for clotting. Heparin interferes with activation and formation of thrombin and delays clotting.

Question 21

3 examples of Romanowsky stain

Answer 21

• Diffquik
• Giemsa
• Leishman’s

Question 22

What stains are used in Romanowsky staining

Answer 22

Methylene blue

Eosin red

Question 23

What is polychromasia - hipochromasia?

Answer 23

Polychromasia - differing intensity of staining of rbc

Hipochromasia - understaining

Question 24

What is Improved Neubauer Haemocytometer?

Answer 24

For counting of WBCs

Question 25

Increased protein level reasons

Answer 25

Dehydration, lactation, infection, neoplasia

Question 26

Decreased protein levels reasons

Answer 26

Hepatic/renal dysfunction, malabsorption, immunodeficiency

Question 27

Raised cholesterol levels

Answer 27

Hypothyroidism, cushings disease, post prandial, diabetes mellitus.

Question 28

Raised urea reasons

Answer 28

Renal failure, renal hypoxia, chronic heart failure, high protein diets, low carb diets, dehydration, urethral obstruction, ruptured bladder.

Question 29

What is pink/red, EDTA tube is used for

Answer 29

Haematology

Question 30

What is orange Lit/Hep tube used for

Answer 30

Biochemistry

Question 31

What is white/brown serum tube used for

Answer 31

All serum tests

Question 32

What is green sodium citrate tube used for

Answer 32

Coagulation studies/prothrombin test

Question 33

What is yellow sodium fluoride/potassium oxalate tube used for

Answer 33

Glucose testing

Question 34

4 types of casts

Answer 34

Hyaline, granular, cellular, waxy

Question 35

What cellular casts can indicate?

Answer 35

Acute renal disease

Question 36

What granular casts can indicate?

Answer 36

Chronic renal disease. Associated with inflammatory change.

Question 37

What is the name of the counting chamber used to count worm ova?

Answer 37

The McMaster slide or Ovassay

Question 38

What worm eggs cannot be counted with McMaster or Ovassay and why

Answer 38

Tapeworm ova as they sink, while roundworms float.