RBC 1

Question 1

what are the 3 things included in a CBC and what is one 4th thing you should ALWAYS do?

Answer 1

erythrogram (RBC)
leukogram (WBC)
thrombogram (platelets)

slide evaluation

Question 2

what is the hormone that stimulates EBC production? When does it get produced and by whom?

Answer 2

erythropoietin
the kidneys detect hypoxemia, which will then release EPO, which will then tell the bone marrow to start making more RBCs

Question 3

what 3 values will go UP in response to the effects of erythropoietin?

Answer 3

RBC count, Hct (hematocrit), Hgb (hemoglobin)

Question 4

what are the 3 major pools of RBCs in the body?

Answer 4

precursor cells in the marrow, blood, and spleen

Question 5

the total process of forming new and mature red blood cells in the bone marrow takes how long?

Answer 5

about 3-4 days to get a metarubricyte (nucelated RBC), and about a week to get peak production

takes around 4 days to see new RBCs in circulation in response to EPO

Question 6

define erythrocytosis
how is it detected on a CBC?

Answer 6

an increased [RBC] in peripheral blood
detected by presence of an increased Hct, increased Hgb, ot an increased RBC count above the normal reference interval. All 3 of these values will usually go up, but if just one goes up it is STILL classified as erythrocytosis

Question 7

what two breeds or kinds of animal usually have an incerased hct normally?

Answer 7

hot blooded horses like thoroughbreds, quarter horses, and arabians, and greyhound dogs

Question 8

what is the difference between erythrocytosis and polycythemia?

Answer 8

erythrocytosis is an increased in hct, RBC count, or hgb
polycythemia is a primary erythrocytosis, meaning it is a neoplastic disorder of bone marrow that results in proliferation of erythroid precursor cells resulting in high numbers of mature RBCs in the blood

Question 9

define hemoconcentration and list two reasons this happens

Answer 9

hemoconcentration is the increased concentration of blood components including the RBCs because of decreased plasma volume

either the patient is dehydrated, or the sample has become dehydrated

Question 10

List two reasons why erythrocytosis is clinically significant

Answer 10

1. extreme erythrocytosis can cause sludging of blood and impair the flow of blood, resulting in poor oxygenation of tissues
2. erythrocytosis may be a reflection of underlying disease like cardiac or pulmonary problems, or renal neoplasia

Question 11

the causes for erythrocytosis can be split into 2 categories which are

Answer 11

relative and absolute

Question 12

relative erythrocytosis can happen due to 2 reasons, list them

Answer 12

dehydration and splenic contraction

Question 13

absolute erythrocytosis is split into two categories. list them and explain the difference between them

Answer 13

primary: a problem with the marrow/blood cells themselves, like polycythemia
secondary: it is hapening secondary to heart, lung, or renal problems elsewhere

Question 14

hemoconcentration is an example of what kind of erythrocytosis and why

Answer 14

relative because either the animal or the sample is dehydrated, meaning there is no actual change to the RBC mass in the body, it just appears so relative to the other components

Question 15

physiologic erythrocytosis happens as a result of what? Is this relative or absolute and why?

Answer 15

happens as a result of splenic contraction
it is relative because there is no actual changes in the RBC mass, it just appears so because many RBCs that were once stored in the spleen have now entered circulation

Question 16

A 5 yo lab named daisy has presented to you for acute diarrhea and vomiting. The owners are very concerned, so you run a CBC. Your [RBC], Hct, and Hgb are flagged for being higher than the upper limit of the reference range. Leukocytosis is also present, and her total protein (TP) value is also high. On physical exam she seems a little bit depressed and had a slightly prolonged skin tent but is otherwise normal. Interpret what is going on here.

Answer 16

hemoconcentration/relative erythrocytosis due to dehydration from diarrhea and vomitting. luekocytosis probably indicates she has an infection as well which also explains the vomiting and diarrhea

Question 17

if you see a marked erythrocytosis on your erythrogram, but the total protein value is within the normal range, what does this tell you?

Answer 17

It is likely not dehydration and more likely to be due to splenic contraction

Question 18

splenic contraction can cause a relative erythrocytosis. Why do animals contract their spleen? Is this a pathologic disease?

Answer 18

splenic contraction happens due to fear, excitement, shock, pain, exercise. Overall results in sympathetic stimulation and release of epinepherine. Dogs, cats, and hot blooded species tend to do this the most

Question 19

describe what polcythemia is

Answer 19

a neoplasia, causing proliferation and production of erythroid cells WITHOUT the influence of EPO so the cells reproduce uncontrollably and do not follow normal checks and balances for cell growth

Question 20

true or false: EPO can have an affect on animals with primary erythrocytosis

Answer 20

false! neoplasms in primary erythrocytosis are NOT under the influence of EPO! they are autonomous

Question 21

secondary erythrocytosis is split into two categories based on the body’s response. Explain them

Answer 21

appropriate response: the animal has heart failure, respiratory disease, or hyperparathyroidism. the response of erythrocytosis is appropirate because the body is compensating for low levels of oxygen, the kidneys detect this and produce EPO which causes the bone marrow to produce more RBCs, leading to an increase in the RBC mass in the body

inapproriate response: a renal neoplasia is present due to a renal tumor that is autonomously producing EPO, leading to an increase in the RBC mass in the body

Question 22

is primarypolcythemia a common diagnosis?

Answer 22

no, it is a diagnosis of exclusion

Question 23

what is poikilocytosis?

Answer 23

when the RBCs have funky shapes and it can be an in vitro artifact

Question 24

_______ is the most common cause of hyperalbuminemia

Answer 24

hemoconcentration/dehydration

Question 25

a classic presentation of dehydration looks like:

Answer 25

-panhyperproteinemia (albumin, total protein, and globulin are all increased)
-azotemia, increased electrolytes
-highly concentrated urine

Question 26

a german shepherd dog 2 years old comes to your clinic because he is having liquidy bloody diarrhea and he is lethargic. This has been happening for only about a day or so. You run a CBC and his Hct is moderately high, his BUN is high, and his albumin and total proteins are low. What does this all mean?

Answer 26

the dog likely has hemorrhagic gastroenteritis

there is erythrocytosis due to the high hct and there is azotemia due to high BUN, and these both support dehydration

the low albumin and TP is likely due to the fact that the dog is losing proteins via the Gi tract (given the bloody diarrhea)

Question 27

A 8 yo FS great dane is brought to you because she has an enlarged heart and she is not acting herself. on CBC she has increased [RBC], Hct, and Hgb. She also has low lymphocytes. On RBC morphology, there were some anisocytosis and echinocytosis. What is your interpretation?

Answer 27

likely an absolute erythrocytosis due to a heart problem and a lymphopenia due to stress. This heart problem will cause renal hypoxia, eventually leading to eythrocytosis via EPO production and initiation from the bone marrow to produce more RBCs. Anisocytosis and echinocytosis are both not clinically relevant.

Question 28

what are anisocytosis and echinocytosis?

Answer 28

anisocytosis: variable red cell size
echinocytosis: a drying artifact where the RBCs sort of look like they have spikes on the outside of them

Question 29

you’re examining a dog blood smear via the miscroscope and you see this. What is this called and should you be concerned?

Answer 29

these are echinocytes, so on a report you would say there is an echinocytosis

this is a drying artifact and not clinically significant

Question 30

what is the term we use to describe when there are RBCs of many sizes showing up on a blood sample?

Answer 30

anisocytosis

Question 31

you are looking at a blood smear and you see this! what is the term for this and are you worried?

Answer 31

these are poikilocytes, so this would be called poikilocytosis. it is normal in calves, deer, goats, and pigs and may be an in vitro artifact. So no I am not worried because it is probably an artifact

Question 32

You’re running a CBC for a regular screening for a cat. Everything is normal except for the platelets, they are flagged as low. Is this cat thrombocytopenic?

Answer 32

You can’t tell for sure unless you look at the blood smear to check for platelet clumps. If the platelet count is slightly low but you do have platelet clumps, the animal is likely not truly thrombocytopenic.