Lecture 3

Question 1

What does “MCV” stand for?

Answer 1

Mean Corpuscular Volume

Question 2

What is the volume per average erythrocyte?

Answer 2

MCV

Mean Corpusular Volume

Question 3

What terminology do you use to refer to the following:

1. MCV within reference interval
2. Increased MCV
3. Decreased MCV

Answer 3

1. Normocytic
2. Macrocytic
3. Microcytic

Question 4

The following is the equation for which value?

(HCT (%) x 10) / [RBC]

Answer 4

MCV

Mean Corpuscular Volume

Question 5

Order the following species by increasing average erythrocyte size:

Dog

Horse

Cow

Cat

Answer 5

1. Cow ~ 5.5 microns
2. Horse ~ 5.7 microns
3. Cat ~ 6 microns
4. Dog ~ 7 microns

Question 6

What are 3 causes of microcytosis? (There are 6 total)

Answer 6

1. Age
2. Breed
3. Liver disease
4. Anemia of inflammatory disease
5. Iron deficiency
6. Artifact

Question 7

Which breeds (4) may naturally have a low MCV (microcytosis)?

Answer 7

Shib

Shar Pei

Akita

Siberian Husky

Question 8

What are the 4 common causes of a high MCV (macrocytosis)?

(There are 4 common causes and 3 less common causes)

Answer 8

1. Common causes:
   
   • Reticulocytosis
   • Breed (Greyhounds)
   • Agglutination
   • Species (Llamas & horses)
2. Less common causes:
   
   • Hereditary macrocytosis (Poodles)
   • FeLV infection
   • Vitamin B12 deficiency

Question 9

What does MCH stand for?

Answer 9

Mean Cell Hemoglobin

Question 10

What is the equation for calculating the MCH (Mean cell hemoglobin) value?

Answer 10

[Hemoglobin] x 10 / [RBC]

Question 11

The MCH is the amount of _____ per average erythrocyte.

Answer 11

Hemoglobin

Question 12

MCH or MCHC

1. Which of these is more useful clinically?
2. Why?

Answer 12

1. MCHC
2. MCHC takes into consideration the size of the RBCs, whereas MCH does not. MCHC is also more accurate.

Question 13

What does MCHC stand for?

Answer 13

Mean Cell Hemoglobin Concentration

Question 14

The MCHC is the average _____ _____ per average erythrocyte.

Answer 14

The MCHC is the average hemoglobin concentration per average erythrocyte.

Question 15

What terminology might you use to describe the following:

1. Increased MCHC?
2. Decreased MCHC?

Answer 15

1. Hyperchromia
2. Hypochromia

Question 16

What are 3 causes of increased MCHC (hyperchromia)?

Answer 16

1. Hemolysis
2. Lipemia
3. RBC shape changes (heinz bodies, spherocytes)

Question 17

What are 2 causes of a decreased MCHC (hypochromia)?

Answer 17

1. Reticulocytosis
2. Iron deficiency

Question 18

MCH and MCHC most often change in the same direction, with one notable exception.

1. What is that exception?
2. What are the MCH and MCHC values?

Answer 18

1. Reticulocytosis
2. MCH generally normal; MCHC often low

Question 19

What does “RDW” stand for?

Answer 19

Red cell distribution width

Question 20

What is anisocytosis?

Answer 20

Variation in cell size

Question 21

What 3 conditions might be associated with an increased RDW (red cell distribution width)?

Answer 21

1. Regenerative anemia (reticulocytosis)
2. Microcytosis
3. Macrocytosis

Question 22

What is another term for reticulocyte?

Answer 22

Polychromatophil

Question 23

What about reticulocytes makes them stain bluer than a mature RBC?

Answer 23

Cytoplasmic RNA stains blue (basophilic)

Hemoglobin stains red (eosinophilic)

Question 24

What is the most important indicator of accelerated erythropoiesis?

Answer 24

Reticulocytosis

Question 25

What 2 types of reticulocytes are found in the circulation of a cat?

Answer 25

Aggregate Punctate

Question 26

In cats: 1. Which type of reticulocyte corresponds to polychromatophils on a smear? 2. Which type of reticulocyte is NOT considered a sign of regeneration? 3. How long is the cell type from #2 in circulation?

Answer 26

1. Aggregate 2. Punctate 3. Several weeks

Question 27

1. Which blood value may suggest a regenerative anemia in a horse? 2. Will this value be increased or decreased with regeneration?

Answer 27

1. MCV 2. Increased

Question 28

An increased in nucleated RBCs is referred to as what?

Answer 28

Rubricytosis

Question 29

True or False: Nucleated RBC count must be determined manually with a microscope.

Answer 29

TRUE Hematology analyzer CANNOT differentiate between nRBCs and WBCs.

Question 30

What are the 3 general causes of anemia?

Answer 30

1. Increased RBC loss 2. Decrease RBC production 3. Increased RBC destruction

Question 31

Describe a normal, healthy response to anemia, ending in production of erythropoietin.

Answer 31

Anemia --\> decreased O2 carrying capacity --\> renal hypoxia --\> erythropoietin released from the kidney

Question 32

What 3 things does erythropoietin stimulate?

Answer 32

1. Erythrocyte progenitors 2. Hemoglobin production 3. Early marrow release

Question 33

How does one assess regenerative anemia in a dog or cat?

Answer 33

Reticulocyte numbers in circulation: Non-regenerative = absent reticulocytes Regenerative = increased reticulocytes

Question 34

What blood characteristics would be present in a ruminant with a regenerative anemia? (there are 3)

Answer 34

1. Increased reticulocytes in circulation 2. Basophilic stippling in RBC 3. Increased nRBCs (rubricytosis)

Question 35

What 3 blood characteristics might suggest a regenerative anemia in a horse?

Answer 35

1. Increased MCV 2. Erythroid hyperplais (bone marrow) 3. Increased PCV over time

Question 36

True or False: An increased nRBC is an indication of regeneration in dogs and cats.

Answer 36

FALSE An increase in nRBCs is only an indication of regeneration in ruminants.

Question 37

What is an appropriate rubricytosis?

Answer 37

An increase in nRBCs WITH a reticulocytosis.

Question 38

What is an inappropriate rubricytosis?

Answer 38

An increase in nRBCs WITHOUT a reticulocytosis.

Question 39

What are the 3 causes of an inappropriate rubricytosis?

Answer 39

1. Damage to bone marrow 2. Decreased splenic function 3. Extramedullary hematopoiesis

Question 40

What are 3 causes of acute hemorrhage? (there are 5 total)

Answer 40

1. Trauma/surgery 2. Coagulation disorder 3. Thrombocytopenia 4. Platelet function disorder 5. Neoplasia

Question 41

What are 3 causes of chronic hemorrhage? (there are 4 total)

Answer 41

1. Parasites 2. GI ulcers 3. Hematuria 4. Hemophila

Question 42

1. What cell type is this? 2. With what type of anemia would you see this?

Answer 42

1. Keratocyte 2. Iron deficiency

Question 43

What finding would be on a peripheral blood smear of a patient with iron deficiency anemia?

Answer 43

1. Fragments (schistocytes) 2. Hypochromasia 3. Keratocytes 4. +/- thrombocytosis