Unit 8

Question 1

What are the normal shapes of RBCs in varying species

Answer 1

Canine: biconcave disc with distinct central pallor

Feline: round with little or no central pallor

Avian, reptiles, and fish: nucleated RBCs

Camellidae: elliptical RBCs

Question 2

How is RBC morphology reported

Answer 2

Cell arrangement
Cell size
Cell color
Cell shape
Structures in or on the cell

Question 3

What is rouleaux

Answer 3

When the RBCs appear in linear stacks

This is NORMAL in horses

Cats and pigs may have slight rouleaux

In other species it is due to increased proteins

May be artifact due to storing for too long before a smear was made or refrigeration

Must be reported (exception: horses or if it is 3+ in cats)

Accompanied by an increase in erythrocyte sedimentation rate (settles out faster because it is heavier)

Question 4

What is agglutination

Answer 4

Irregular spherical clumps of cells

May look like rouleaux in early stages -long thin extensions from cytoplasm

as it progresses with will take on a muddy brown color and melted appearance

Occurs due to a reaction between antibodies and antigens present in RBCs surface causing them to stick together

Question 5

How can you differentiate rouleaux from agglutination

Answer 5

Mix the blood with 50:50 ratio of warm isotonic saline

Make a smear

If the formation disappears it was rouleaux (due to proteins) if it does not it is agglutination (will not break apart due to antibodies)

Question 6

Normocytic

Answer 6

Cells of normal size

Question 7

Macrocytic

Answer 7

Cells larger than normal

Question 8

Microcytic

Answer 8

Cells smaller than normal

Question 9

Anisocytosis

Answer 9

Variation in size (common in cattle and rats)

Question 10

Macrocytic erythrocytes

Answer 10

Generally twice the normal size
(In dogs they only need to be slightly bigger to be classified as macrocytic)

These have increased MCV

Normal in miniature poodles

These are normally reticulocytes (immature)

Question 11

Microcytic erythrocytes

Answer 11

Smaller than normal

Accompanied by hypochromasia (less color)

MCV will be decreased

Common reason: iron deficiency or chronic bleeding

Question 12

Normochromic

Answer 12

No abnormalities in color

Question 13

Polychromasia/reticulocytes

Answer 13

Polychromasia: darker in color than normal

With wright’s stain they appear macrocytic and blue tinged -these are immature RBCs -blue staining is due to organelles being present

Usually accompanied by an increased number of nucleated RBCs, hypersegmentation, howel jolly bodies

Question 14

True or false
You don’t see reticulocytes with horses

Answer 14

TRUE

Horses release macrocytic RBCs that are not polychromatic (no reticulocytes -only way to find out if they are regenerating cells is through bone marrow)

Question 15

Increased vs lack of polychromasia indicates what

Answer 15

Increase: regenerative anemia (good)

Lack: non regenerative anemia (bad)

Question 16

Hypochromasia

Answer 16

Cells are more pal than normal

Increased central pallor

Due to a decreased hemoglobin concentration within the cell

Macrocytic RBCs can appear hypochromic because of enlarged cell size

Can be due to poor technique

Normally accompanied by Microcytosis (iron deficiency)

Question 17

Hyperchromasia

Answer 17

Cells that are stained darker than normal

RBCs have a fixed maximum capacity for hemoglobin so over saturation is not possible

Hyperchromasia is usually seen on spherocytes or microcytic cells

Question 18

What are schistocytes

Answer 18

RBC fragments

Due to shearing of the cell from intravascular trauma

Question 19

What are echinocytes

Answer 19

Will be seen on every smear

Normal all look the same: short evenly spaced blunt to sharp surface projections that are uniform in shape and size

Often an artifact from drying the slide too slowly, being refrigerated or put in a hypertonic solution

Classified as type 1 or 3

Question 20

What are type 1 vs 3 echinocytes

Answer 20

Type 1: cremated cells: very short projections

Type 3: burr cells: very thin, quill like projections

Question 21

What are acanthocytes

Answer 21

Irregularly speculated RBCs

Very few unevenly spaced surface projections of variable size and shape

Can be normal in cattle, often underlying pathology in larger numbers in SA

often only a problem if in large numbers

Hemageosarcoma

Paint like splotches

Question 22

What are drepanocyges

Answer 22

Also called sickle cells

Normal in deer and goats

Shaped like bananas

Question 23

What are Keratocytes

Answer 23

RBCs containing 1 or more spicules/projections that look like horns or crescents

May appear to contain a vacuole

May occur in small numbers in healthy animal or large numbers with pathology

Question 24

What are spherocytes

Answer 24

Darkly staining RBCs that don’t contain central pallor (look Hyperchromic)

Smaller than normal RBCs with normal
MCV

almost perfectly round

Usually Only detected in dogs

Seen with immune mediated hemolytic anemia

Question 25

What are leptocytes

Answer 25

A large cell membrane to volume ratio which causes the membrane to fold in on itself Cell looks like it has 2 areas of central pallor Usually due to improper filling if EDTA tubes Considered an artifact if the areas of central Pallor are all perpendicular to the feathered edge Servers types

Question 26

What are the 3 main types of leptocytes

Answer 26

Codocyte: target cells: dense central area separated by a peripheral clear zone, up to 50% are normal in dogs, uncommon in other species, may be artifact or seen with pathology Stomatocyte: contain an oval central pallor, seen with Alaskan malamutes with hereditary stomaticytosis, significance is unknown, looks like a mouth Knizocytes: has a dark bar if hemoglobin across the center of the cell, looks like it has 2 mouths

Question 27

What are elliptocytes/ovalocytes

Answer 27

Normal in camelids These are oval shaped RBCs Abnormal in other species

Question 28

What are eccentrocytes

Answer 28

Believed to be a precursor to the keratocyte Loss of central pallor Have 1 or 2 large clear zones outlined by the membrane Often accompany Heinz bodies Can be artifact

Question 29

What are dacrocytes

Answer 29

Cells that are shaped like a tear drop If all the tails point in the same direction it is artifact

Question 30

What are ghost cells

Answer 30

Cells that have been leached off their hemoglobin All you see in the cell membrane (faint outlines)

Question 31

Define poikilocytes

Answer 31

This is a blanket term that means the erythrocytes have an abnormal shape Only used when none of the other descriptions match the cell

Question 32

What is basophilic stippling

Answer 32

Looks like blue dusting in the cell Caused by residual RNA “Blue spots” If this is real it will be in focus while the cell is in focus (unlike stain sediment)

Question 33

What are Howell jolly bodies

Answer 33

Nuclear remnants These are small, round, dark blue inclusions of variable size usually just off center Has sharp edges and are in focus when the cell is in focus

Question 34

What are Heinz bodies

Answer 34

Oxidative denaturation if hemoglobin 1-5% normal in cats Appear as small, eccentric, pale blue structures within RBCs, they appear to stick out or protrude from the edge (blip projecting off the edge) In cats they are single and large, in dogs they are small and multiple Test: stain for reticulocytes -Heinz’s bodies will stain darker Seen with toxicities

Question 35

Nucleated RBCs

Answer 35

Slightly larger than mature cells and with have a dark nucleus Usually associated with pathology -significant if there is a lot

Question 36

What are sideritic granules

Answer 36

Stainable iron granules within mitochondria and lysosomes (generally on the side of cells and are lighter than howell jolly Bodies) Extremely rare

Question 37

What parasites are dogs often affected with

Answer 37

Dirofilaria immitis Babesia canis

Question 38

What parasites are horses most commonly affected with

Answer 38

Babesia caballi

Question 39

What parasites are cats most commonly affected with

Answer 39

Mycoplasma haemofeilis

Question 40

How can you differentiate stain sediment

Answer 40

Stain sediment is often seen between the RBCs in equal Proportions as on top of the RBCs

Question 41

What do the mycoplasma haemofeilis look like

Answer 41

Small, oval to slightly rod shaped structures alone the cells periphery as single organisms or in chains/rings Agglutination is usually present too

Question 42

What is ehrlichia and anaplasma

Answer 42

Transmitted by arthropods/ticks Gram negative, rod shaped, spherical, coccoid or ring shaped bodies with RBCs Diagnose with ELISA snap test

Question 43

What is Babesia canis

Answer 43

Protozoan infection transmitted by ticks Produces severe hemolytic anemia Usually appears as tear drop shaped organisms in RBCs Stain darker

Question 44

What do viral infections look like in blood

Answer 44

Distemper inclusions rarely seen in dogs When found they appear as faint blue to magenta round structures of variable size and number Usually seen in polychromatophilic RBCs Can be seen in neutrophils as well