RBC Infectious Agents and Reticulocytes Flashcards Preview

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Flashcards in RBC Infectious Agents and Reticulocytes Deck (25)
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1

What are these and in what species are low numbers of them normal?

Howell-Jolly bodies

normal in cats and horses

increased in regenerative anemia, splenectomy, glucocorticoid administration

2

What are these and seeing what % of them in a cat blood smear is normal? What can they be caused by otherwise?

Heinz bodies - up to 5% normal in cats; increased with diabetes, lymphoma, and hyperthyroidism

oxidative damage - onion and garlic ingestion

other: splenectomy (dogs), propylene glycol in soft food (cats), zinc toxicity (dogs), RX (acetaminophen, methylene blue, methionine, phenazopyridine, menadione), napthalene/moth balls, propofol anesthesia (cats)

SKUNK MUSK

3

In what circumstances would you see heinz bodies in large animals?

After eating: wild/domestic onions, kale and other brassica species (ruminants), red maple leaves (horses and alpacas), copper toxicity (sheep and goats), lush winter rye (florida cattle

selenium deficient cattle on St. Augustine grass

post-parturient New Zealand cattle on perennial ryegrass

phenothiazine in horses

4

What are these and what RBC morphology are they similar to in cause

Eccentrocytes - similar to Heinz Bodies because also caused by oxidant injury 

Causes: acetaminophen, onions, garlic, propofol, viamin K, antagonist rodenticides in dogs, red maple toxicity in horses, IV hydrogen peroxide in a cow, enzyme deficiencies in horses

5

Seeing this - is it a good or bad sign if you see it in an anemic cow? 

Good - means anemia is regenerative in ruminants

it is basophilic stippling - aggregates of ribosomes and polyribosomes

*can indicate lead toxicity 

6

What are these? What do they indicate?

siderotic inclusions - focal stippling

may involve iron-laden mitochondria and/or autophagic vacuoles

can indicate zinc toxicity

chloramphenicol and hydroxyzine therapy

hemolytic anemia

dyserythropoiesis

pyridoxine deficiency

7

Name some infectious agents of erythrocytes. 

Protozoal organisms: babesia, theileria, cytauxzoon

Rickettsial : anaplasma

Mycoplasmal

Bacterial: bartonella

Viral: distemper 

8

"spiderman" cells = what disease?

babesia

9

This parasite achieves schizogony in what blood cell?

lymphocytes

this parasite = theileria 

species in USA ruminants are usually non-pathogenic

10

name this parasite!

cytauxzoon felis

11

name this parasite! hint: can be transmitted by ticks 

anaplasma

12

Name this infectious agent. Hint: this slide is from a cat.

Mycoplasma 

13

Image is from the same infectious agent with two different stains. Bottom stain is Diff-Quik. What is the infectious agent?

Distemper virus

14

What is anemia and its clinical signs?

low circulating RBCs for the species, breed, gender, and age of animal

a sign of underlying disease, not a disease

clinical signs - due to decreased delivery of O2 to tissues, weakness, lethargy, poor peripheral perfusion (pale MM, sclera), tachycardia, poor pulse quality, systolic murmur, tachypnea, dyspnea

15

Seeing marrow precursor cells in a blood smear indicates what?

regenerative anemia 

16

How long does reticulocyte maturation take in dogs?

24-48 hours

17

What is the difference between the cells marked "A" and the cells marked "P" in the slide?

aggregate reticulocytes vs. punctate reticulocytes - punctate are older in the development process, distinguishable from normal RBCs using Wright's Giemsa stain; only aggregate retics look polychromatophilic with Wright's Giemsa stain 

18

These two slides show two different stains of what RBC developmental stage?

reticulocytes (in dog blood) 

two stains are: wright-giemsa on left, new methylene blue on right 

19

How long does it take reticulocytes to mature in dogs? cats?

dogs - one day 

cats - aggregate to punctate in one day, punctate to mature in a week or more 

20

What is a relative reticulocyte count and how can you use it?

percentage of all erythrocytes that are reticulocytes 

dogs: less than 1% = healthy, nonanemic

cats: 0-0.5% aggregate and 1 to 10% punctate reticulocytes = healthy nonanemic

RUMINANTS AND HORSES DO NOT NORMALLY HAVE RETICULOCYTES IN BLOOD

21

Why do you not see reticulocytes in equine blood smears?

retics almost never released into circulation - maturation confined to the bone marrow 

22

If anemia is present and your reticulocyte concentration is 5000 cells/microliter... are you concerned?

Yes - 

1-10,000 = nonregenerative to very poorly regenerative

10,000-60,000 -nonregenerative to poorly regenerative

60k-200k - mildly to moderately regenerative

200k-500k - very regenerative 

23

What does the presence of a regenerative response tell you about the cause of an anemia?

anemia caused by hemorrhage or increased erythrocyte destruction, not decreased erythrocyte production 

24

How many days does it take for an animal to increase its RBC synthesis and release reticulocytes from bone marrow?

3-4 days

25

How does the degree of anemia affect the reticulocyte percentage?

Less blood cells total makes fewer reticulocytes seem more important 

ie. 1 reticulocyte out of 10 blood cells is 10% but 1 reticulocyte out of 4 blood cells is 25%