Erythrocyte Abnormalities
Clinical Pathology,
Ms. Canga

Erythrocyte Morphology
 Different species have different _________ RBCs with varying degrees
of ___________________________.
 Dogs have _____________ RBCs (~________ µm in diameter)
 Cats, horses, cows, sheep, goats (3-4 µm)
 Llamas and camels have ______________________ (oval) RBCs
 Deer have _________________-shaped RBCs
 Birds, fish, amphibians, and reptiles have ______________________,
elliptical RBCs.
 Human RBCs are about the same size as those of ______________.
Relative sizes of RBCs
Chicken
Llama
Reptile
Deer
Normal RBC Morphology
Feline blood. Normal erythrocyte morphology. Feline RBCs are smaller than dog
erythrocytes, exhibit a slight amount of crenation, and have a minimal area of
central pallor
Review
 There are 5 ways to classify erythrocytes as normal or
abnormal:
 1) ________________________________________________
 2) ________________________________________________
 3) ________________________________________________
 4) ________________________________________________
 5) ________________________________________________
Arrangement on a Blood Film
 How should cells appear on film?
 Abnormal formation
 _____________________ formation
 _________________________________________
Rouleaux Formation
 Rouleaux formation
 Grouping of RBCs that appear ________________
 Normal in _________________
 Seen with increased _______________ or
___________________ concentration in blood
 May appear as an _________________
 Refrigerated blood not allowed to return to room
temperature
 May be seen if blood has been held too long before
preparation of smear
Rouleaux as an Artifact
 As you learned in Lab Pro, rouleaux formation may be
an artifact.
 If it IS an artifact and not a true medical condition in
the patient, ____________ may be added to the
sample.
Rouleaux Formation
Agglutination/Auto-agglutination
 Agglutination is caused by an __________________ that
coats the RBC causing bridging or clumping of the cells.
 Typically occurs in _________________________ disorders
 Agglutination MAY appear as __________________ on
occasion
 To differentiate between agglutination and rouleaux, saline
is added to the sample.
 On the next slide, are the EXACT procedures for adding
saline to your sample:
Adding Saline to Confirm Rouleaux
 When rouleaux is suspected, ____________________ all tubes in
question.
 Carefully remove ___________ /____________with transfer
pipette, leaving the cells undisturbed. Discard/use plasma or
serum
 Add 2 drops of ________________ to test tube and mix well.
 ________________________the tube
 Gently re-mix the red cells and perform smear
 _________________ will disperse,
______________________________will NOT
Comparison in the Monolayer
Agglutination can Affect WBCs too!
Variation in Color
 Called _______________________
 ____________________________
 ____________________________
 Calculated through the ___________ (Remember the
formula?)
 Classifies cells as ____________________ or
_______________________
Polychromasia
 Variation in color usually associated with
__________ and ____________________
 ________ production begins right before cell loses
nucleus
 ____________ intensity decreases as metabolic
activity ____________________
 ________ increases in intensity as ________
production ______________________.
Polychromasia
 Recall that the _______________ the cell in the RBC
maturation series, the more dark blue the staining due
to increased __________________ activity.
 Mature RBCs stain _________ because they have their
full complement of ________.
 ______ production begins right before cell loses
______________; immature RBCs with some Hb
present stain ______________________ because
there is still some metabolic activity going on within
the cell.
Hypochromasia
 ____________ staining intensity of RBCs
 Caused by insufficient ________ concentration due to
_________ deficiency (Chronic ____________ loss or
______________________)
 Cell will appear normally stained around
__________________ with a much paler central region.
 Hypochromasia is almost always accompanied by
_____________________ . (Decreased __________)
 Determined by a decreased ______________
Hypochromasia
Hyperchromasia
 Increased staining intensity of RBCs
 Immature RBCs = larger and darker
 Hyperchromasia based on _______ concentration
(_______) cannot exist…
 Presence of _______________, ___________________,
and _____________can interfere with tests and
_______________________ increase MCHC
 _____________________ often seen
 are __________________and __________________but can
have normal cell volume. (Cell may be ________________)
 May be seen in mismatched _________________________
Hyperchromasia/Spherocytes
Canine blood. Regenerative anemia with spherocytes. Anisocytosis is due to macrocytic cells
and spherocytes, which are smaller than normal and lack central pallor. Spherocytes are
associated with hemolytic anemias due to immune disease or fragmentation. The
polychromatophilic RBC with a rod- shaped area of central pallor (arrow) is a stomatocyte
Poikilocytosis
 Variations in the __________________ of RBCs
(poikil ~ irregular)
 Not a __________________________
 A general term to encompass nondescript variations in
______________ of erythrocytes that are scattered
throughout the blood film.
Poikilocytosis
Note: Poikilocytosis, anisocytosis, and polychromasia are present on this slide.
Schistocytes “Helmet Cell”
 RBC fragments resulting from shearing of red blood cell by
_________________________________.
 May be seen with
_______________________________________ (DIC) or with
________________________
 Expect to also see ________________________________ on
blood film of animals with DIC
 Can be caused by excess _______________deposition,
malformation of _______________________, or excessive
_________________________in the blood
 Common name is “__________________________”
Schistocytes
Acanthocytes “Spur Cells”
 Have irregular membrane projections of _______________________
length and diameter with __________________________tips
 _______________________sized and spaced
 May be seen in blood smear of:



Cats with _____________________________________,
Dogs with ___________________disease or
____________________________of the liver
 Represent __________________ alteration rather than
________________________
 Commonly called “________________”
Acanthocytes
Echinocytes “Burr Cells”
 __________________ change
 Resulting from _____________ change in blood, altering cell
_____________________
 May appear __________________ or ruffled, with relatively
_____________ sized and spaced, short, _________ projections
 Associated with ____________ disease, ____________________
or rattlesnake _________________________in dogs
 Can be _____________________ if excess of _______ is present
Echinocyte formation
Echinocytes
Echinocytes as“Crenation”
 __________________ Change
 ______________________
 Slow ________________ of blood film
 _____________________EDTA tube
 Affects the ________________ of the cells on a blood film
Crenation
Drepanocytes “Sickle Cells”
 ________________________ with pointed ends
 Result of alteration in __________ due to low
___________ tension
 Normal finding in ___________, Angora _________,
and some ___________
Drepanocytes
Keratocytes “Helmet cell”
 Also called “________________”
 Keratocytes are believed to result from
____________________________________
 Can also result from _________________ injury
found with ___________ deficiency
 Presence of keratocytes has also been associated
with ____________________,
_________________, ________________________,
and various _________________ diseases.
Keratocytes and Pre-keratocytes
Anulocytes “Punched-out cells”
 ____________ shaped RBCs that form as a result of a
loss of the membrane ____________________.
 Cell cannot return to normal shape after passing
through a narrow _____________________.
 May be seen in any _______________ disease.
 Can also occur due to low _______ concentration or as
an ____________________.
Anulocytes (Punched-out cells)
Dacryocyte “Teardrop cells”
 _________________ shaped RBCs with a single
____________________ or _______________end
 May be seen in _________________________
diseases or ____________ and ________________
disorders of dogs.
 Can be an ______________ . Check to see if the
_______________ are all pointing in the __________
direction.
Dacryocytes “Tear-drop Cells”
Eccentrocyte
 Characterized by a shifting of the _______________ to one side
of the RBC
 ____________ portion of membrane is ragged and poorly
_______________________________.
 Form under conditions of ___________________ stress
 May be seen with ____________________________Anemia
Eccentrocyte
Codocytes (Leptocytes)
 Characterized by an increase in membrane
_________________ _________
 Include all of the following cells:
 __________________________
 __________________________
 __________________________
 __________________________
Target Cells (Bull’s eye Cell)
 Resembles a ____________ with a bulls-eye
 Have central area of _____________ surrounded by area of
pallor
 _________________ of cell contains band of _______
 A few may be seen in _____________ smears
 May be associated with __________ deficiency, _________,
___________ diseases, and some _______________
disorders.
Target Cells
Folded cells and Stomatocytes
 Folded cells have a ______________ _____appearing central
pallor
 _____________________ have a transverse, raised fold
extending across the center of the cell and a clear, _________like pale region in the center.
 Both may be caused by a change in membrane _____________
associate with ______________ disease
 Both are considered an ___________________ if the areas of
pallor are ________________________ to the feathered edge.
Stomatocyte
Stomatocytes
Folded Cells
Knizocytes (Barr Cells)
 Appear to have a bar of _________ through the central pallor.
 Commonly observed in chronic ______________ disease
 May be observed in any acute ______________ dysfunction
 Caused by an alteration in the ______________ content of
cell membrane
Knizocytes or “Barr Cells”
Some Poikilocytes at a glance
Test yourself! 
Presence of Structures on/in Erythrocyte
 Many different abnormalities caused by variety of different
conditions.
 __________________________
 __________________________
 __________________________
 __________________________
 __________________________
 __________________________
 __________________________
 __________________________
 __________________________
Howell-Jolly bodies
 __________________________ nuclear remnants observed in
young RBCs during their response to
__________________________ anemia
 Normally, as cells containing nuclear remnants pass through the
_______________ , _________________ cells remove the
remnants.
 Therefore, HJBs may be seen with ________________ disease or
in an animal with the _____________removed.
Howell-Jolly bodies
Basophilic Stippling
 Observed in RBCs that contain abnormal, residual ___________.
 Small, dark blue “__________________” within the RBC.
 Occasionally seen in __________________ RBCs in
_____________ cats.
 Characteristic finding with __________________________ in
dogs.
Basophilic Stippling
Heinz Bodies
 Particles of __________________________, resulting from
oxidative injury, attach to RBC _______________________.
 They stain blue with _________________________________
and appear as a _________________ area with Diff-quick stain.
 Seen in _________________________ and ______________
ingestion in cats and dogs
 HBs are often increased in concentration with diseases such as
_____________________ , ______________________, and
______________________________ in cats
 Normal cat blood may have up to _____%
Heinz bodies
Reticulocytes
 Immature RBC; contains _________________ (ribosomes) and
residual RNA that are lost as the cell matures.
 A.k.a. ‘____________________________ RBC’ (when stained
with _______________________ and not NMB)
 NMB causes visualization of clumping of residual organelles,
referred to as ‘______________________’.
 Cats have two forms: ___________________ and
_____________________.
Reticulocytes
Canine Distemper Viral Inclusions
 Seen in RBCs of dogs with _________________.
 __________________________
 Variable in _________, __________, ________ and
_________(faint blue to magenta).
 More frequently seen in ________________________
RBCs than _______________RBCs.
 Can also be seen in ___________________ and
_____________________.
Viral Distemper inclusions
Blood Parasites that Affect RBCs
 Parasites may be present ____________ or _____ the
surface of RBCs
 Stain ___________________ and drying
________________ are sometimes confused with RBC
parasites.
Babesia spp.
 _____________________ or __________shaped,
______________________, paired inclusions
 Transmitted via ______________
 Causes ___________________ anemia
 Commonly identified at __________________ edge of blood
smears
 Seen in __________, __________, __________, __________,
and ______________
Babesia spp.
Mycoplasma haemofelis
 Formerly known as: ____________________________
 Disease = Feline Infectious __________________ Anemia
 May be, coccoid, rod-shaped, or ringlike structures, but usually
appear as short, dark purple ________on the __________________
of RBCs
 Organisms usually detach from the RBC when placed in
_________________________.
 Cyclic ____________________, organisms may be numerous, scarce
or not found in a given blood sample – examine blood at different
_____________of the day
Mycoplasma haemofelis
Mycoplasma haemocanis
 Formerly known as ___________________________
 Rare; Usually only occurs in
________________________ or immunosuppressed
dogs.
 Organism appears as a chain or small cocci or rods that
stretch across _____________ of RBC.
 Chains may appear “_____________________.”
Mycoplasma haemocanis
Cytauxzoon felis
 Small,
ring or _______________-shaped bodies in red
cells
 Causes a ______________ disease in cats
 Transmission is by ____________
 Rare cause of _________________ anemia
 No known _________________
Cytauxzoon felis