Lecture 2 8/27/24

Question 1

What is polychromasia?

Answer 1

morphologic description of what a reticulocyte looks like on routine blood smear

Question 2

What do spherocytes indicate?

Answer 2

immune-mediated hemolytic anemia

Question 3

What are spherocytes?

Answer 3

RBCs with membrane-bound antibodies that are removed by macrophages; removal of part of the membrane causes the cells to have a spherical shape

Question 4

What does agglutination indicate?

Answer 4

immune-mediated hemolytic anemia

Question 5

What is rouleaux?

Answer 5

linear arrangements of RBCs due to increased globulins

Question 6

What are heinz bodies?

Answer 6

a projection off of a RBC that indicates oxidant injury

Question 7

What are eccentrocytes?

Answer 7

RBCs with a white “fingernail” appearance that indicates oxidant injury

Question 8

What are schistocytes?

Answer 8

torn or fragmented RBCs

Question 9

What are the potential causes of schistocytes?

Answer 9

-disseminated intravascular coagulation
-hemangiosarcoma
-cardiac disease

Question 10

What is basophilic stippling?

Answer 10

diffuse stippling of RBCs on a routinely stained blood smear

Question 11

What are the potential causes of basophilic stippling?

Answer 11

-regenerative anemia in ruminants
-lead toxicity in any species

Question 12

What are the mechanisms of anemia?

Answer 12

-hemorrhage
-hemolysis
-decreased RBC production in the bone marrow

Question 13

Which mechanisms of anemia are regenerative?

Answer 13

-hemorrhage
-hemolysis

Question 14

Which mechanism of anemia is non-regenerative?

Answer 14

decreased bone marrow production of RBCs

Question 15

What does it mean for an anemia to be regenerative?

Answer 15

bone marrow responds appropriately to RBC loss by increasing RBC production

Question 16

What findings in the bone marrow and blood are expected in a regenerative anemia?

Answer 16

bone marrow: erythroid hyperplasia
blood: increased numbers of reticulocytes

Question 17

What findings in the bone marrow and blood are expected in a non-regenerative anemia?

Answer 17

bone marrow: erythroid hypoplasia and/or ineffective erythropoiesis
blood: normal or decreased numbers of reticulocytes

Question 18

What is the caveat with regenerative anemia?

Answer 18

it takes 3-4 days following hemorrhage or hemolysis for the bone marrow to begin releasing increased reticulocytes into the blood

Question 19

What is the sole definitive way to distinguish regenerative vs non-regenerative anemia?

Answer 19

absolute reticulocyte count

Question 20

What are the possible patterns seen on CBC that could indicate a regenerative anemia?

Answer 20

-increased MCV and decreased MCHC
-normal MCV and MCHC, but with MCV at the high end of normal and MCHC at the low end of normal

Question 21

What are other possible CBC/blood smear findings that can indicate regenerative anemia?

Answer 21

-increased nRBCs
-Howell-Jolly bodies
-increased RDW
-basophilic stippling

Question 22

How do horses uniquely present with regenerative anemia?

Answer 22

-do not release reticulocytes into circulation during a regenerative response
-instead release macrocytic RBCs

Question 23

How is anemia definitively classified in horses?

Answer 23

bone marrow evaluation

Question 24

What indirect indicators of regenerative anemia can be present in horses?

Answer 24

-increased RDW
-increasing MCV
-identified cause of hemorrhage or hemolysis

Question 25

When is pre-regenerative anemia unlikely?

Answer 25

if an animal has been sick for more than a few days but is not showing a reticulocyte count

Question 26

When is pre-regenerative anemia more likely?

Answer 26

-acute traumatic blood loss -acute hemolytic anemia w/ abnormalities on microscopic exam

Question 27

Why are no changes in CBC values seen a few minutes after a hemorrhagic episode?

Answer 27

even though the animal is hypovolemic, there has not been enough time for proportional changes to occur in the blood

Question 28

Which changes in CBC values can be seen a few hours after a hemorrhagic episode?

Answer 28

-decreased HCT -decreased protein

Question 29

What causes the changes in CBC values seen a few hours after a hemorrhagic episode?

Answer 29

movement of water into the vasculature to replace lost volume, which dilutes the blood components

Question 30

Which changes in CBC values can be seen 3-5 days after a hemorrhagic episode?

Answer 30

-decreased HCT -normal to increased MCV -normal to decreased MCHC -increased reticulocytes -normal to decreased protein

Question 31

What are examples of chronic external hemorrhage causes?

Answer 31

-GI hemorrhage -ectoparasites

Question 32

What are the expected CBC results with chronic external hemorrhage?

Answer 32

-regenerative anemia -possible decrease in total protein -potential iron deficiency if duration is long enough

Question 33

Why can chronic hemorrhage result in iron deficiency?

Answer 33

-most iron used for erythropoiesis is recycled from aged RBCs -loss of RBCs from the body prevents iron recycling -over time, this can result in bone marrow iron store depletion

Question 34

What are the consequences of iron-restricted erythropoiesis?

Answer 34

-anemia -impaired reticulocyte production -decreased CHr -decreased MCHC -decreased MCV