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415 Cards in this Set

  • Front
  • Back
why use a standard red top tube
standard CBC/Chem, endocrine, serology
why use a serum separator tube?
stops glucose from being degraded over time
Anemia
A decrease in the hemoglobin value, the packed cell volume, or the erythrocyte count of more than two standard deviations below the mean normal.
why use EDTA
cbc/wbc/rbc/platelets, binds Ca to prevent coagulation
Anisocytosis
Variation in the size of cells, usually the erythrocytes.
what is important when using EDTA?
use the rigth size tube for amount of blood, otherwise RBCs will shrink
what is special about heparin as an anticoagulant?
only one that does not bind Ca
Aplastic
Cessation of blood cell formation
What does the PCV/Hct measure & which is more accurate?
% of whole blood that is RBCs

PCV considered more accurate
electrophoresis: what does the height of the peak indicate?
concentration of protein
Band form
a granulocyte with a nucleus that is unsegmented and ribbon like - stab, nonfilamented - juvinal
What factors can cause errors in measured RBC count?
species RBC size variation, counting of large platelets, not counting small RBCs (microcytes), or agglutination
What factors can artifically increase measured Hb concentration?
lipemia, Heinz bodies, WBC > 50,000/µl, hyperbilirubinemia
what is mesured on routine electrophoresis?
total protein, albumin, globulin
Basophilic strippling
Erythrocyte that shows blue staining, basophilic granules scattered throughout.
is globulin a measured or calculated value?
calculated: T prot- alb
What is MCV?
mean corpuscular volume = average RBC volume (size)
Buffy coat
The layer of leukocytes, thrombocytes and nucleated erythroncytes, if any, that collect immediately about the erythrocytes in sedimented or centrifuged whole blood.
alpha globulins
acute phase proteins. Made by the liver in reponse to inflammation. They are produced quickly and are produced as long as there is active inflammation
What is MCHC?
mean corpuscular hemoglobin concentration = average conc. of Hb per RBC volume
Color index:
the ration between the ammount of hemoglobin and the number of erythrocytes
beta globulins
a mix- some acute phase proteins, lipoproteins, complement, some immunoglobulins
Crenation
Shrinkage of cells in a hypertonic souution with the formation of irregular margins and a number of prickly points. Also seen in smears caused by dirty glassware, slow drying, extreme temperatures, and poor smearing technique.
What is RDW?
random distribution of RBC weight: distribution of RBC's based on their volume (size)
gamma globulins
immunoglobulins
what does an increase of gamma globulins indiciate?
immune response
Dohle bodies
Small (1 to 2 microns) roiund or oval, fray-blue bodies in the cytoplasm of neutrophic leukocytes thought to be due to incomplete utilization of RNA during maturation of the cytoplasm.
What is the name for an

a) increase
b) decrease

in MCV?
a. macrocytosis

b. microcytosis
why do a TP from a refractometer and a CBC not match?
measured in different ways from different samples
Erythrocytopenia
A decreased number of erythrocytes in the perpheral blood
What is the name for an

a) increase
b) decrease

in MCHC?
a. hyperchromasia

b. hypochromasia
Erythrocytosis
The presence of an increased srythrocyte count above normal and associated with an increased total blood volumne
fibrinogen
acute phase reactants that is measured to detect inflammation, particularly in horses and cattle
Erythropoiesis
The production of erythrocytes
What is the name for any abnormally shaped RBC?
poikilocyte
Fibrin
The end product of the clotting mechanism, which forms a network of fibers that enmesh the formed elements of blood
how is fibrinogen measured
it precipitates out when the sample is heated, so the protein is measured before and after heating
What is an acanthocyte & with what disorders is it associated?
spiculated RBC w/ single or multiple, irregular, blunt, rounded projections

liver dz (more in cats), microangiopathy, HSA
Granulocyte
A leukocyte that contains specific cytoplasmic granules(neutrophilis, eosinophils, basophils) regardless of the stage of differentiation.
what can increalse productoin of fibrinogen?
inflammation
Granulocytosis
Presence of increased numbers of granulocytes in the blood.
What is an keratocyte & with what disorders is it associated?
spiculated RBC w/ 1 or 2 pointed projections

Fe deficiency, liver disorders
Heinz bodies
An intraerythrocytic mass of denatured globin, irregular in shape and appearing as refractile granules when slightly out of focus. This latter property is responsible for their being called erythrocyte refractile bodies.
most common cause of decreased fibrinogen?
excesssive consumption during coagulation in DIC
What is an echinocyte & with what disorders is it associated?
spiculated RBC w/ numerous short, evenly shaped surface projections

snake bite envenomation, crenation, dehydration
what does the serum concentration of albumin reflect?
a balance between hepatic synthesis and normal catabolism
Hemolysis
Descruction of erythrocytes by dissolution or lysis.
What is an spherocyte & with what disorders is it associated?
small dense RBC lacking central pallor

IMHA, Heinz body anemia, transfusion
Howell-Jolly bodies
Small, round, densely staining bodies in the srythrocytes that are considered to be nuclear remnants and are usually eccentric in location.
pathologic processes tthat affect serum concentration include:
changes in hydration status, changes in the rate of hepatic synthesis, and processes leading to an accelerated loss of albumin.
Hyperchromasia and hypercromatic
Terms which when applied to the microscopic appearance of a cell or cells of the srythrocytic series, indicate that the cells seem to have a more intense hemoglobin color due to an increased thickness of the observed cell
What is an schistocyte & with what disorders is it associated?
fragmented RBC

DIC, microangiopathy
Hyperchromic
Because of a significant increase in mean corpuscular hemoglobin is not known to occur, it is recommended that this term be avoided
what can reduce hepatic syntehsis of of albumin?
hepatic failure, starvation/malnutrition/aa deficiency and it can be reduced in response to acute or chronic inflammation
What is an eccentrocyte & with what conditions is it associated?
RBC w/ condensed Hb in one area of cell

oxidative damage to Hb
albumin is a ____ acute phase protein
negative
What is a nucleated RBC & with what conditions is it associated?
Immature RBC w/ a nucleus in peripheral blood

intense BM stimulation, BM injury, after splenectomy, lead poisoning
Hypochromasia and Hyperchromatic
indicate that the cells show a significant decrease in density of the characteristic hemoglobin color for the stained or unstained cell. This may be due to either thinness of the cell, decreased concentration of hemoglobin or both
what are the main clinically significant globulins?
immunoglobulins made by lymphocytes (and acute phase proteins made by the liver)
Hypochromic
An adjective describing a blood picture in which the srythrocytes have a mean corpuscular memoglobin concentration or saturation index and usually a mean corpuscular hemoglobin of color indx more that two standard deviations below the mean normal determined by the same method on the blood of healthy animals of the same age and sex group
What is a Howell Jolly body & with what conditions is it associated?
Basophilic nuclear remnants usually near edge of RBC (Romanowsky stains)

accelerated RBC production
what can result in increased globulins?
acute or chronic inflammation, hydration status. Some tumors
What is a Heinz body & with what conditions is it associated?
Round structures (representing denatured Hb) on internal RBC membrane (NMB stain)

oxidative damage to Hb: onions, acetaminophen, Red Maple (horses), propofol (w/ repeated use), 1-2% clinically asymptomatic in cats
when does the A:G ration become useful?
when more than one process is occuring at the same time
Leukemia
Neoplastiv disease arising in hemopoietic tissue in which the type cells appear in the blood.
What is basophilic stippling & with what conditions is it associated?
RBCs containing residual RNA, appear as multiple, small blue dots w/ Romanowsky stains

ruminants: regeneration
other species: lead poisoning
Leukocytosis
An increase in the number of circulating leukocytes above the normal range
if the disease affects both albumin and globulin, what happens to the ratio
remains the same
Leukopenia
A decrease number of circulating leukocytes below the normal range
What is agglutination & with what conditions is it associated?
Grape like aggregation of RBCs that will NOT disperse w/ saline dilution

IMHA
Macrocyte
An srythrocyte having a diameter exceeding that of the normal range.
what affect does dehydration have on the ratio?
ratio unaffected, both increase equally
Macrocytic
Erythrocytes have a mean corpuscular volume exceeding by more that two standard deviations the mean normal determined by the same method on the blood of healthy animals of the same age and sex group when this condition is not doe to riculosytosis alone.
What is Rouleaux formation & with what conditions is it associated?
Grouping of RBCs resembling a stack of coins that disperses w/ saline dilution

- horse: normal
- cat, pig: slight amount normal
- other: chronic inflammation, multiple myeloma
Microcyte
An erythrocyte having a diameter below the normal range
what will happen to the ratio if the animal is dehydrated and has chronic inflatmmation?
both will increase by the glubulin will increase relatively more, so the ratio will decrease
Microcytic
An adjecitive describing a blood picture in which the srythrocytes have a mean corpscular volume of volume index more that two standard deviations below the mean normal determined by the same method on the blood of healthy animals of the same age and sex group
What is crenation & with what conditions is it associated?
RBC w/ even distribution of sharp spikes (shape change occurs in all cells in given area)

artifact (old blood, delayed drying of blood film, improper anticoagulant ratio)
Neutropenia
Deficency of neutrophilic leukocytes in the blood
what is measured directly from an automated instrument?
total nucleated cell count, hemoglobin, RBC count, MCV, platelet count
Neutrophilia
An increase in the total number of neutrophils in the blood
What are 4 parasites that may be found w/in RBCs?
Anaplasma
Babesia
Mycoplasma
Ehrlichia
three calculate values
HCT, MCHC, RDW
Normocytte
An erythrocyte having a normal diameter
What is polycythemia?
increase RBC count, PCV, Hb
Normocytic
Blood picture in which the erythrocytes have a mean corpuscular voulmne with in the normal range
what should you always do when running bloodwork?
perform a blood smear to look at cell morphology
Pelger-Huet anomaly
A rare herediatary condition associated with myeloproligerative disorder where neutrophils lack the usually nuclear segmentation
What is relative polycythemia?
increased PCV, & Hb with normal total RBC mass
Poikilocyte
An erythrocyte with an abnormal shape, not to be confused with distortion that results from faulty technique
impedance method
cells impede current passing through aperture- counts and sizes particles. The main discriminator is size.
Polychromasia, polychromatic, polychromatophilia
Erythrocytes that show a faint bluish tint due to a mixture of the characteristic colors of hemoglobin and basophilic erythrocytic cytoplasm.
What are the 2 main causes of relative polycythemia?
dehydration: ↑ PP, dry skin & mucous mems, ↑ BUN, creatinine, USG (can calculate PP:fibrinogen ratio in LA)

splenic contraction: all parameters normal, may occur in horses & cats
Polycythemia
A state of the blood characterized by an increased number of erythrocytes
optical method-flow cytometry
laser hits each cell; light scatter counts, sizes, IDs cells
Reticulocyte
Any nonnucleated cell of the erythrocytic series containing RNA, which when supravitally stained with new methlene blue or brilliant cresyl blue will have discernible granules or a diffuse network of fibrils.
What is absolute polycythemia?
increased PCV & Hb w/ ↑ in total RBC mass d/t ↑ erythropoiesis (less common than relative)
Rouleaux formation
The arrangement of erythrocytes in a roll or column, with their flat surfaces facing, in which they appear as figures resembling stacks of coins.
common sources of error with blood analyzers:
RBC size overlap (species, esp cat), giant platelets, clumped platelets. Sample problems: agglutinatoin, lipemia, hemolysis
What is the cause of primary absolute polycythemia?
bone marrow disorder --> uncontrolled RBC production (RARE)
Shift to the left
An increase in the immature forms of the granulocytic series in the blood
dog RBC size
60-72fl
Shift to the right
An increase in the percent of older cells (hypersegmentation)
What are the 2 causes of secondary absolute polycythemia?
both cause increased EPO production

appropriate: d/t chronic hypoxia (CV dz, pulmonary dz, etc.)

inappropriate: : d/t renal dysfunction or neoplasia that produces ↑ EPO

can be iatrogenic: too much epogen
cat, horse, cow RBC size
39-52 fl
Spherocyte
A spheroid erythrocyte of decreased diameter in relationship to its volume and having the microscopic appearance of a hyperchromativ microcyte
What is anemia?
↓ RBC count, PCV, & Hb
sheep rbc size
25-35 fl
What 3 schemes are used to classify an anemia?
RBC indices (MCV, MCHC)
BM response (regenerative vs. non-regenerative)
underlying cause
llama rbc size
21-29 fl (note oval shape)
Toxic Neutrophil
A neutrophil characterized by toxic granules, basophilia of the cytoplasm, vacules, or condensation of nuclear chromatin.
What are the 3 main underlying causes of anemia, what are the associated changes in plasma protein, & how would you diagnosis each?
↓ RBC production
- PP NORMAL or ↑ (d/t inflammation)
- dx: reticulocytes, bone marrow

blood loss
-very early in acute blood loss, PCV will be NORMAL b/c both RBCs & plasma being lost at same proportion
-later, interstitial fluid moves rapidly into blood  ↓ PCV, ↓ PP
-dx: hx, lesions

↑ RBC destruction (lysis)
-may be intravascular or extravascular hemolysis
-PP NORMAL or ↑ (d/t inflammation)
-dx: icterus, RBC changes
goat rbc size
15-25 fl
What are some causes of microcytosis?
iron deficiency
PSS
normal in Akitas, Japanese Shiba

implies abnormal Hb synthesis --> smaller cells
What are some causes of macrocytosis?
regeneration
FeLV
may be normal in Poodles
false (d/t agglutination)

assoc. w/ increased erythropoeisis --> release of retics (larger than mature RBCs)
What are some causes of hypochromasia?
Fe deficiency
reticulocytosis
What are some causes of hyperchromasia?
hemolysis (true hyperchromic cells don’t exist)
What is the most common type of anemia based on RBC indices?

Is it usually regenerative or non-regenerative?
normocytic normochromic

usually non-regenerative
ddx for microcytic hypochromic anemia

Is it usually regenerative or non-regenerative?
Fe deficiency (most common), PSS, anemia of chronic dz, etc.

poorly or non- regenerative
ddx for macrocytic hypochromic anemia
regenerative anemia (reticulocytosis)
in MCHC?"
"a. hyperchromasia
ddx for macrocytic normochromic anemia
FeLV (altered RBC maturation), may be normal in miniature & toy poodles
what does a differential leukocyte do and how is it performed?
determine percentage of different cell types. Performed on wright stained blood film
What signs are evidence of regeneration on a blood smear?
reticulocytosis
basophilic stippling (bovine)
macrocytosis (horse)
Howell Jolly bodies
anisocytosis
do you use the percentage of leukocytes for interpretation?
no, use the absolute number (% * WBC)
What are the unique factors assoc. w/ regeneration in

a. horses
b. cows
c. cats
a. no reticulocytosis, look for macrocytosis, look in bone marrow

b. inconsistent release of retics; look for basophilic stippling

c. 2 types of retics
-aggregate: similar to dog retics (indicates a recent stimulus (a few days))
-punctate: cells contain dots & not aggregated RNA (indicates a stimulus 1-3 weeks previously)
why should you do a blood film evaluation?
look at erythrocyte and leukocyte morphology, confirm automated analyzter results, look for platelet clumps, giant platelets, look for blood parasites and abnormal cells
What are the 2 major causes of regenerative anemia?
blood loss

hemolysis
where should you analyze a blood film?
at the monolayer
What are the early pre-regenerative responses during acute blood loss?
↑ blood volume: shift ECF to IV space

↑ RBCs: splenic contraction
what are reticulocytes?
immature RBCs that still contain organelles. They stain with vital dyes such as new methylene blue. Correspond to polychromatophils on the wright stained blood film
why is a reticulocyte count important?
to classify anemias
calculate absolute retics:
(% retics in 1000 RBCS) * RBC count
what can nucleated RBCs be due to?
strongly regenerative anemia, splenic dysfunction, marrow injury, etc
Corrected WBC count
nucleated cell count * (100/100+nRBCs)
absolute nRBC
% * TNC count
how are nRBCs commonly reported?
# per 100 WBC
What other hemogram or chemistry abnormalities are associated w/ blood loss anemia?
decreased plasma protein
What other hemogram or chemistry abnormalities are associated w/ hemolytic anemia?
normal or ↑ PP hyperbilirubinemia hemoglobinemia
hemoglobinuria
RBC morphology (spherocytes, parasites, Heinz bodies)
What is extravascular hemolysis & what is a commonly associated serum chemistry change?
abnormal RBCs phagocytosed by MPS in spleen & liver (more common)

hyperbilirubinemia usually present
What are some causes of extravascular hemolysis?
IMHA, oxidative damage, intrinsic RBC defects, parasites
What RBC morphologic changes are associated w/ IMHA?
anisocytosis, polychromasia (regeneration), agglutination, spherocytes, ghost cells, ↑ MCV (d/t retics & agglutination)
What is the Coomb's test?
used to help dx IMHA

detects Ab &/or complement bound to patient’s RBCs

positive ≠ 1º IMHA
What RBC morphologic changes are associated w/ oxidative hemolytic anemia?
Heinz bodies, eccentrocytes

methemoglobinemia

also called Heinz body hemolytic anemia
What is intravascular hemolysis & what are 2 prominent features that help to dx it?
RBCs lysed w/in bloodstream: poorer px

hemoglobinemia, hemoglobinuria
What are some causes of intravascular hemolysis?
complement mediated, bacterial toxins, parasites, hereditary, chemicals/toxins
What are some causes of fragmentation of RBCs (subset of intravascular hemolysis)?
microangiopathy: abnormal small vessels (see acanthocytes, schistocytes)
ex. HSA, vasculitis

DIC: fibrin deposited in vessels (schistocytes)
What CBC findings are consistent w/ nonregenerative anemia?
no retics
no polychromasia
variable anisocytosis
N to ↑ nRBCs
N to variable MCV & MCHC
hx: chronic
What is the main defect associated w/ non-regenerative anemias?
decreased erythropoiesis = hypoproliferative BM d/t inadequate # of precursors or inadequate stimulus
What are some causes of non-regenerative anemia?
Fe deficiency
ACD
lack of EPO
BM damage
myelophthisis
What are some causes of iron deficiency anemia?
chronic blood loss: parasites, ulcers (most common)

dietary deficiency: young animals (uncommon)

malabsorption: intestinal dz
What lab findings are consistent w/ iron deficiency anemia?
microcytic hypochromic anemia

non-regenerative

↓ serum iron

↓ bone marrow iron stores

↓ ferritin (storage form of iron)

thrombocytosis: megakaryocytes respond to EPO
What is the most common anemia of domestic animals?
anemia of chronic dz
What lab findings are consistent w/ anemia of chronic dz?
initially, normocytic, normochromic

over a long time, can progress to microcytic, hypochromic

non-regenerative

↓ serum iron: iron sequestered in MPs

normal ferritin

thrombocytosis: d/t inflammatory mediators
How could you differentiate non-regenerative anemia as being caused by Fe defeciency or ACD?
give patient some iron
improvement = Fe deficiency
no improvement = ACD
What is aplastic anemia & what are some causes?
depletion of all 3 cell lines in blood & BM

causes: estrogen, infections (Ehrlichia, FelV), drugs, plants, radiation
What are 3 main underlying causes of thrombocytopenia?
increased destruction (common)

increased consumption or sequestration

decreased production
What are the functions of platelets?
plug endothelial lesions, clot formation, release soluble mediators
How do platelets form & what controls their production?
produced by “flaking off” from megakaryocytes

thrombopoietin controls production
What are common causes of thrombocytopenia d/t increased destruction?
immune mediated
1º (autoimmune): Abs against self Ag on megakaryocytes &/or platelets
2º: Abs against non-self Ag on platelet surface
What are common causes of thrombocytopenia d/t increased consumption or sequestration?
DIC: most common

sequestration (ex. spleen): transient, not common

massive hemorrhage: would take huge blood loss
What are common causes of thrombocytopenia d/t decreased production?
marrow suppression d/t drugs, toxins, infectious agents, neoplasia, etc.

↓ platelets w/ ↓ WBCs &/or ↓ RBCs
What are some characteristics of platelet regeneration?
large platelets

↑ MPV

BM: megakaryocytic hyperplasia (↑ # of megakaryocytes)
What are 3 main categories of thrombocytosis?
physiologic: common
reactive: common
myeloproliferative/neoplastic: rare
What are causes of physiologic thrombocytosis?
transient mobilization: minutes to hours (d/t splenic contraction)

exercise & epinephrine
What are causes of reactive thrombocytosis?
↑ production by BM d/t:
thrombopoietin
erythropoietin (anemia)
inflammation
What is Evans' syndrome?
concurrent IMHA & IMTP
In what species are lymphocytes usually more prevalent in peripheral blood than neutrophils?
cattle
What is meant by the term left shift?
indicates presence of immature granulocytes (usually neutrophils) in blood
What is a regenerative left shift?
leukocytosis in which mature neutrophils outnumber immature neutrophils
What is a degenerative left shift?
immature neutrophils outnumber mature neutrophils

indicates excessive demand &/or inadequate supply (more guarded px)
What is a leukemoid rxn?
very high neutrophil count w/ a severe, but orderly left shift

indicates severe inflammation but a responding bone marrow
What are the CBC changes consistent w/ leukemia?
presence of neoplastic hematopoietic cells in circulation

leukocytosis; immature forms: often 1 stage overrepresented; disorderly maturation
What are the functions of neutrophils?
chemotaxis: cell migration to site of inflammation

engulfment/killing: release of granule contents (enzymes that kill bacteria)
What are band neutrophils?
immature neutrophils that has a nucleus w/ parallel sides
What are hypersegmented neutrophils?
neutrophils w/ 5 or more distinct nuclear lobes

indication of prolonged transit time (glucocorticoids)
What are toxic neutrophils & what 3 morphologic features do they possess?
indicate inflammation (↑ demand for neutrophils)

↑ basophilia of cytoplasm, vacuolated (foamy) cytoplasm, Dohle bodies (bluish angular cytoplasmic inclusions
What are the 3 neutrophil pools found in the bone marrow?
proliferating pool: contains BM cells capable of division
-time from myeloblast --> metamyelocyte: ~2.5 days

maturation pool: contains BM cells NOT capable of division
-transit time: ~2.5 days

storage pool: contains mature BM cells (subset of maturation pool)
-constitutes body’s reserve of neutrophils
-usually have ~5 day supply in BM storage
-wimpy in cattle
What are the 2 neutrophil pools found in blood?
marginated pool: neutrophils that have marginated along blood vessel walls
-same size as circulating pool in dogs, horses, calves
-3x larger than circulating pool in cats

circulating pool: neutrophils in larger blood vessels moving in the main stream of blood
-pool that’s sampled when taking a blood sample for CBC
What WBC characteristics are consistent w/ inflammation w/ a mild to moderate tissue demand (ex. abscess?)
neutrophilia +/- left shift, monocytosis, toxic neutrophils may be seen
What WBC characteristics are consistent w/ inflammation w/ continued tussue demand (ex. pyometra?)
neutrophilia w/ regenerative left shift & toxic neutrophils, monocytosis
What WBC characteristics are consistent w/ inflammation w/ an excessive tissue demand (ex. Salmonellosis?)
neutropenia, degenerative left shift, toxic neutrophils

insufficient storage cells for demand & BM has not had time to respond
What are some causes of neutropenia?
sequestration

increased margination (ex. endotoxins: lasts 1-3 hrs)

decreased production: BM usually reveals myeloid hypoplasia (caused by damage to myeloid precursors): FeLV, feline panleuk, Ehrlichia, toxicities, drugs, neoplasia

ineffective production, increased destruction: rare
What is Pelger-Huet Anomaly?
hyposegmented nuclei of neutrophils, eosinophils, basophils

normal function

concern is not to mistake for a left shift inflammatory process
What is physiologic leukocytosis (epinephrine response)?
causes by epi (fear, excitement) or sudden strenuous exercise

response time almost immediate, but is short-lived (~30 minutes)
key features: mature neutrophilia, lymphocytosis

most pronounced in cats, horses

dogs: usually mild neutrophilia only
What is corticosteroid induced leukocytosis (stress response)?
caused by either endogenous or exogenous steroids

response takes several hours to develop w/ peak rxns in 4-8 hrs

key features: mature neutrophilia, lymphopenia, eosinopenia, monocytosis (not a consistent finding, even in dogs)

dogs have most classic response

lymphopenia is most consistent & occasionally the only finding
What are some causes of lymphocytosis?
epinephrine response
immunological stimulation
infectious dz: Ehrlichia, bovine leukemia virus
lymphocytic leukemia
Addison's: stressed dog lacking a stress response
normal in cows, swine
What are some causes of lymphopenia?
stress response
acute infections (esp. viral)
loss of lymph
radiation/chemo
immunodeficiency (less common)
What are the functions of monocytes?
phagocytosis & degradation of ingested material

present antigen to initiate lymphocyte responses
What are some causes of monocytosis?
think CHRONIC INFLAMMATION 1st!: tissue destruction, necrosis, intracellular or fungal organisms

stress response: esp. in dogs

immune mediated disorders
What are the functions of eosinophils?
regulation of type I (immediate) & type III (delayed) hypersensitivity rxns

antiparasitic properties

bacterial phagocytosis (less so than neutrophils)

activation of plasminogen
What are some causes of eosinophilia?
parasites
hypersensitivity rxns
hypereosinophilic syndromes
neoplasia
What are the functions of basophils?
hypersensitivity (histamine release)

follow eosinophils

possible cytotoxic effects
against tumor cells

possibly anti-parasitic
What are some causes of basophilia?
w/ eosinophilia: parasites, hypersensitivity, neoplasia

rare to have w/o eosinophilia: basophilic leukemia
What is leukemia?
neoplastic cells of BM origin in circulation --> leukocytosis
What is lymphoma?
neoplasm of lymphocytes arising as a solid tissue mass in organs other than BM (ex. lymph node, liver, spleen, GI, etc.)

MUCH MORE COMMON THAN LEUKEMIA
What is myeloproliferative dz?
proliferation of granulocytic, megakaryocytic, erythrocytic, &/or stromal CT cells in BM
What are myelodysplastic syndromes?
ineffective hematopoiesis w/ resultant peripheral blood cytopenias (ex. FeLV)
How is leukemia classified?
based on natural duration of dz
-acute: very little differentiation of neoplastic cells (mostly blasts); duration of illness is short; poor px
-chronic: well-differentiated neoplastic cells; may live for months or years after dx

based on cytology
-myeloproliferative: neoplastic proliferation of non-lymphoid cells (ex. neutrophils, eosinophils, basophils, monocytes, RBCs, megakaryocytes)
-lymphoproliferative: neoplastic proliferation of lymphocytes
what is special about the retic count in horses?
horses do not release retics into peripheral blood
cats have what two forms of reticulocytes?
aggregate and punctuate. Aggregates correspond to polychromatophils. Punctuate have distinct dots and no clumping. Aggregate mature to punctuate
in cats, what is the best indicator of active hematopoiesis?
aggregate retics
what color do polychromatophils stain with Wrights?
blue
what affect do polychromatophils have on MCV? MCHC?
increase MCV, decrease MCHC.
what does increased polychromasia suggest?
regenerative anemia
most common cause of hypochromasia in dogs and camelids?
iron deficiency
hyperchromasia
does not exist- increased MCHC does not naturally occur
breed associated microcytosis
akita, shiba inu
one major cause of microcytosis
portosystemic shunt
do spherecytes affect microcytosis counts?
no- they may appear small but usually have a normal volume
most common cause of macrocytic red cells
regenerative anemia
how do spherocytes form in IMHA?
macrophages ecognize antibody bound to red cells and remove part of the red cell membrane, causing the red cell to reform as a sphere
what, besides IMHA, can result in spherocytes?
heinz body anemia, zinc toxicosis, post blood transufsion, microangiopathic injury
schistocytes
red cell fragments, resulting from shearing of red cells by intravascular trauma
schistocytes can occur with _____ due abnormal blood flow and localized DIC. _____ are often present as well
hemangiosarcoma; acanthocytes
schistocytes may be seen along with kertocytes in
severe iron deficiency
three other diseases that can result in schistocytes
glomerulonephritis, liver dz, heart failure
keratocytes
formed from physical or checmical injury to red cell (can be secondary to iron deficiency, oxidative damage, or microangiopathic dz processes)
keratocytes are susceptible to intravascular trauma and may progress to
schistocytes
acanthocytes are thought to result from
changesi n the lipid content of red cell membranes
acanthocytes hve been associated with
altered lipid metabolism (lipid dz, hepatic lipidosis) and hemangiosarcoma
echinocytes
spiculated, numerous short, evenly spaced, uniform projections
echinocytes have been associated with
renal disease, lymphoma, chemo, electrolyte abnormalilies, and envenomation
type three echinocytes
seen with rattlesnake and copperhead envenomation- 24-48 hours after envenomation
eccentrocytes are the result of _____ and may be seen along with ______
oxidative injury; heinz bodies
codocytes
target cells with no real diagnostic significance
rouleaux vs agglutination
agglutination forms grape like clusters rather than "coin rolls". Agglutination can be confirmed with a saline agglutination test (rouleaux will disperse, agglutination witll not)
what does agglutination strongly suggest?
IMHA
heinz body appearance
small circular structure within or protruding from the red cell. Stain dark blue with vital stains.
what are heinz bodies
denatured Hgb resulting from oxidative damage
species that is more prone to heinz body formation
cats
howell jolly body appearance
small round basophilic inclusions on wright's stained blood film
when are howell jolly bodies normal
in small numbers
what do increased numbers of howell jolly bodies indicate?
increased hematopoiesis (Regenerative anemia) or splenic dysfunction
basophilic stippling reflects
aggregated ribosomes in the cells
when can basophliic stippling be seen?
intensly regenerative anemias in dogs and cats, and any regenerative anemia in ruminants. If no regenerative anemia, can suggest lead poisoning
erythroparasites in cats
mycoplasma haemofelis and cytauxzoon felis
m. haemofelis apearance
small rod shaped organisms on the red cell periphery or as ring shaped structures on the cell
c. felis appearance
small signet ring shaped piroplasms
what kind of anemia is associated with c. felis
non regenerative
erythroparasites in dogs
mycoplasma haemocanis, babesia gibsoni, babesia canis
m. haemocanis appearance
small chains of organisms across the surface of the red cell
effects of dehydration on PCV
it increases
three basic mechanisms of anemia:
blood loss, blood destruction, decreased production
how can you tell if an anemia is regenerative?
there is an appropriate bone marrow response- immature red cells are being released, (marked regeneration will raise the MCV and decrease the MCHC). Need to know reticulocyte count
describe a macrocytic, hypochromic anemia
increased MCV, decreased MCHC, probably regenerative anemia
before you decide that an aenmia is non-regenerative, what must you know?
if enough time has passed for the bone marrow to mount a response
in ruminants, what degree of reticulocytosis indicates a regenerative response?
any
corrected retic %
retic% * (Patient PCV / Normal PCV)
Normal dog PCV? Cat?
dog: 45, cat:37
10/10 rule of thumb
if PCV is 10%, retics should equal 10% to be regenerative. If you half the PCV, double the retic count. (in dogs)
what findings suggest hemorrhage (Acute)?
low total protein, evidence of bleeding, TCP (marked TCP), acanthocytes/schistocytes
what findings suggest hemorrhage (chronic)
evidence of GI hemorrhage, low/normal total protein, thrombocytosis, morphological changes typica of iron deficiency
morphological changes typical of iron deficiency
microcytosis, hypochromasia, keratocytes, schistocytes
what findings suggest hemolysis?
normal total protein, agglutination, sphereocytes, red cell parasites, hemolyzed serum, hemoglobinuria, icterus, hepatosplenomegaly, many large heinz bodies/eccentrocytes, exposure to known oxidants, schistocytes/keratocytes
hemolysis may be
intravascular or extravascular
two signs of intravascular hemolysis
hemoglobinemia and hemoglobinuria
which anemias tend to be more strongly regenerative: those due to hemolysis/bleeding into body cavities OR those due to external blood loss
those due to hemolysis or bleeding into body cavities
IMHA findings
severe anemia, strongly regenerative, associated with inflammatory leukogram. Sphereocytes/agglutination often present. Coombs test can be performed.
Evans syndrom
IMHA + immune mediated destruction of platelets resulting in TCP
potential complication of severe cases of IMHA
DIC
any diseases that causes chronic blood loss may result in an ______ anemia
iron deficiency
DIC is
uncontrolled activiation of the coagulation and fibrinolytic cascades through the body. There is widespread coagulation AND the potential for bleeding (platelets/coag factors have been consumed). Usually TCP, microangiopathic injury.
anemia of chronic disease (inflammatory dz)
mild, non regenerative. Normocytic, normochromic.
anemia of CRF
normocytic, normochromic. Look for clues on Chem panel
anemia of endocrinopathies
mild, normocytic, normochronic nonregenertive (hypthyroid, hypoadrencorticism)
felv induced anemias
macrocytic, normochromic. Aplastic.
normocytic/normochronic
most non regenerative anemias
macrocytic/hypochromic
most regenerative anemias
macrocytic/normochromic
some regenerative anemias (horses), FELV induced non regenerative anemia
microcytic, hypochromic
iron deficiency. Could be portosystemc shunt (if PCV is normal)
microcytic, normochromic
some iron deficiencies, some portsystemic shunts
hyperchromic
artifact
which type of polycythemia is most common?
relative
results of dehydration
relative polycythemia, increased total protein. Leukocyte and platelet numbers normal
erythrocyte redistribution
cause of relative polycythemia- splenic contraction. (horses/cats)
which form of absolute polycythemia is most common?
secondary
the number of neutrophils in circulation at any point in time represents the balance between:
production in the marrow and utiliztion in tissues
neutrophils are an important part of the ______
acute inflammatory process
lymphocytes of ruminants are usually
as large as neutrophils
reactive lymphocytes
have deep blue cytoplasm, more irregular nucleus and indicate antigenic stimulation
large granular lymphocytes
have distinct small magenta (azurophilic) granules in their cytoplasm and may represent either t-cells or NK cells
monocyte appearance
greyblue cytoplasm, vacuoles, light purple granules. Typically larger than neutrophils. Nucleus can be any shape, but normally bean shaped and less clumped "lacy" chromatin compared to neutrophils
left shift
increased concentration of immature neutrophils in blood (bands/metamyelocytes). This can be either: increase in absolute numbers above the reference range OR more than 10% immature cells in a neutropenic animal
two types of left shift
regenerative: segmented neutrophils outnumber the immature forms. Degenerative: immature forms outnumber the segmented neutrophils (neutropenia with a left shift)
toxic change
morphological change in cytoplasm of neutrophils. Result of accelerated production. Changes include more basophilic cytoplasm, dohle bodies, foamy vacuolation, toxic granulation, giant neutrophiles, and ring-shaped nuclei
dohle bodies
grey blue aggreages of endoplasmic reticulum in toxic neutrophils
hypersegmented neutrophils
5 or more distinct lobes, associated with aging
leukemoid response
extreme leukocytosis/neutrophliia due to inflammation that mimcs granulocytic neoplasia
myelodysplastic syndrom is considered a ______ state
pre-leukemic
where is myelodystplastic syndrome most recognized?
in felv cats
are toxic neutrophils and degenerate neutrophils the same thing?
NO
degenerate neutrophile
neutrophils not in peripheral blood (ie, in a cytology specifm). Reflects unhealthy environment often associated with bacterial toxins. Changes include nuclear swelling, cell lysis, etc.
pelger huet anomaly can mimic a
left shift
what is the typical result of most inflammatory processes?
neutrophilia
presence of a left shift always indicates
inflammation
very severe acute inflammation results in
neutropenia with a left shift
significance of neutropenia with a left shift in domestic animals? In cattle?
domestic animals: poor prognostic signs. Cattle- typical response.
cattle have low ____ reserves and slow ______ capacity
marrow reserves, proliferation capacity
how do horses respond to inflammation? What test is also useful in horses to diagnose inflammation?
respond with neutrophilia without a marked left shift. Fibrinogen concentrtion test
excitement response
immediate shift of cells from marginated pool to circulating pool. Effect is mature neutrophliia and lymphocytosis. NO left shift.
rule of thumb for excitement response neutrophilia
up to 2x the upper reference range is consistent with excitement (3x in cats). More than that is likley chronic inflammation
steroid response-
shifts lymphocytes from circulation to tissues. Mature neutrophilia and lymphopenia +/- monocytosis. Magnitude of neutrophilia similar to excitement response.
common cause of significant lymphocytosis
lymphocytic leukemia (lymphoblastic or chronic lymphocytic)
what is chronic ehrlichiosis associated with?
marked lymphocytosis, with the morphology of LGLs
what is significant about the LACK of lymphopenia in a sick animal?
should consider hypoadrenocorticism
most common causes of eosinophilia
ecto and endo parasites
what is significant about cat platelets?
typicall 2x the size of other species (platelets can be counted as RBCs based on size)
the interpeation of bone marrow is directly related to the peripheral blood picture at:
the time of the bone marrow sampling
normal PCV, neutrophlilia, and Left shift. Bone marrow shows increase in the M:E ratio. Could indicate
granulocytic hyperplasia present in the marrow
what is required for adequate interpreation of the bone marrow findings?
concurrent CBC
indications for bone marrow aspirate
unexplained cytopenias, potential malignancies involving the marrow, infection infolving the marrow, FUO, radiographic lytic bone lesions, unexplained hypercalcemia
dysproteinemia
abnormal concentrations of a normal blood protein
negative acute phase protein
concentration decreases in response to inflammation (ie, albumin)
what affect does inflammation have on fibrinogen in horses and cattle?
it increases
which is usually higher: TP from refractometer or from chemistry profile? Why?
the refractometer. Usually done on plasma rather than serum, wich lacts fibrinogen and some other coagulation proteins
why is the margin of error of fibrinogen important?
there is no real clinical difference between a fibrinogen of 600 and one of 700 if the margin of error is 200mg/dl.
in animals with bleeding disorders, are you interested in increased or decreased fibrinogen?
decraesed
can decreased fibrinogen be detected with a heat precipitation method?
no
how can you detect decreased fibrinogen?
quantitative method based on thrombin time
effect of hydration status on albumin
dehydration will tend to increase serum albumin concentrations. Overhydration will decrease (globulins are affected to the same degree)
effect of hepatic synthesis on albumin
liver failure (severe) can decrease concentration
high serum albumin is highly specific for
dehydration
effect pf liver disease on total globulin concentration
usually not below reference intervals
which immunoglobulins are sometimes found in the beta region?
IgA and IgM
what does a broad, hill-like increase indicate?
incraeses in many proteins that are all running together on the gell
what does a small narrow peak indicate?
increase in one specific proteins
why is electrophoresis usually run?
to evaluate marked increases in globulin fraction of serum proteins. To differentiate increases in alpha and beta globulins (usually acute phase responses) from incraeses in gamma globulins (chronic inflammation or Ig producing tumors)
what does the shape of the peak seen with gamma globulins indicate?
broad peaks indicate chronic inflammation, narrow peaks (same as or narrower than albumin) indicate immunoglobulin producing tumors
what, besides inflammation, can increase fibrinogen?
dehydration- raises F proportioanlly with TP
if fibrinogen is incraesed but does not make up more than 10% of the total progein, what is still possible?
acute inflammation, but may be just due to dehydration
main cause of decraesed fibrinogen
DIC
panhypoproteinemia
hypoalbuminemia + hypoglobulinemia
causes of panhypoproteinemia:
overhydration/excessive fluid therapy. Blood loss, protein losing enteropathy, exudative skin lesions, high protein effusions,
what causes hypoalbuminemia with normal to increased globulins?
liver failure, malnutrition, acute/chronic inflammation, glomerular disease
how can loss of both protein fractions result in hypoalbuminemia with normal to increased globulins?
possible that globulin just did not drop enough to leave the reference interval, or the animal started out with an increased globulin concentration (due to inflammation/immune stimulation)
what can cause hypoglobulinemia with normal/incraesed albumin?
FPT, decrease in globulins is almost always the result of a lack of immunoglobulins
what can cause hyperalbuminemia only?
dehydration
what can cause hyperalbuminemia with hyperglobulinemia?
dehydration (this is more typical than increased albumin alone)
what can cause hyperglobulinemia with normal/decreased albumin
incraesed production of globulins (acute inflammation, chronic inflammation/immune stimulation, lymphoid neoplasia). Also, dehydration if the animal started out with low albumin due to a selective hypoalbuminemia - ie, glomerular dz or lvier failure
diseases that typically result in a polyclonal respones?
ehrlichiosis, leishmaniassis, chronic pyoderma, etc.
what does a monoclonal peak usually signify?
a lymphoid neoplasia
define hemostasis
physiologic cessation of bleeding
why does coagulation only occur with vascular injury?
coagulation factors are mostly present in an inactive form. The endothelial cells that line blood vessels passively/actively function to inhibit coagulation.
true or false: there are always forces both favoring and opposing coagulation actively occuring
TRUE
initial event in hemostasis
reflex constriction of local blood vessels
platelet adhesions
the first cellular event, where platelets line up along the injured area
what activates platelets?
adhesion.
platelet agonists
secreted by activated platelets, recruit and activate additional platelets to form an aggregation
primary hemostasis
the process of forming a platelet plug at the site of injury
what does the platelet plug do?
it stops bleeding from very small wounds. It is not very stable. In larger wounds, the blood pressure would disrupt the plug
soluble coagulation factors
a group of proteins produced by the liver that act in sequential order to activate each other (coagulation cascade). Fibrinogen is eventually converted to fibrin at the site of the platelet plug.
secondary hemostasis
the process of coagulation factors producign fibrin to stabliize the platelet plug
Why is it important to divide coagulation into ‘primary’ and ‘secondary’ hemostasis?
The clinical bleeding episodes that you see with defects of primary hemostasis are sometimes different than those seen with defects of secondary hemostasis. Sometimes, you can guess which system is affected from the clinical signs. Also, lab tests usually evaluate either primary or secondary hemostasis. This allows you to quickly determine where the problem is, reducing the number of possible causes
what does platelet adhesion require?
a serum protein called von Willebrand factor
is von willebrand factor involved in secondary hemostasis?
not directly
vWF is the only protein that can:
adequately mediate platelet adhesion in vessels with high sheer force
thrombocytopenia
most common cause of abnormal bleeding
receptor for vWF
platelet glycoprotein 1b
receptor for fibrinogen
glycoprotein IIb/IIIa
important biochemical pathway required for normal platelet function
arachadonic acid metabolism that results in the production of thromboxane A2 (TXA2).
The major things needed for primary hemostasis to occur normally
(1) adequate numbers of platelets, (2) normal platelet function, and (3) von Willebrand factor. These are your differentials for a defect in primary hemostasis.
arrangement of the coagulation cascade
two arms: intrinsic and extrinsic systems that terminate in a common pathway
factors involved in intrinsic pathway
XII, XI, IX, VIII
factors involved in extrinsic pathway
VII
factors involved in common pathway
X, V, II, I
**What are the vitamin K dependent factors**
II, VII, IX, and X KNOW THESE!!
which factor has the shortest half life (and would become depleted first if vitamin K antagonists were ingested)
VII
when faced with a bleeding animal you need to first determine
if it is a hemostatic defect vs trauma/disease induced hemorhate
signs assocated with defects in primary hemostasis
petechial hemorrage (usually with TCP), bleeding from mucosal surfaces, slow prolonged oozing of blood
signs assocated with defects in secondary hemostasis
large hematoma formation, bleeding into body cavities, frank hemorrhage
BMBT
buccal mucosal bleeding time
BMBT-
measures the amount of time it takes to stop bleeding from a small, standardized stab incision. Usually less than 3.5 minutes. Not a very sensitive test.
some animals with a primary hemostatic defect will have a normal
BMBT
most common cause of abnormal bleeding of any kind
TCP
most common cause of low platelet count in cats?
artifact due to platelet clumping
macrothrombocytopenia
cavalier king charles, abnormally large platelets. Asymptomatic, usually no clinical bleeding episodes
automated platelet counts are frequently
inaccurate
most common of the inherited bleeding disorders
von willebrand dz
platelet function defects can be ___ or ___
inherited or acquired
tests of secondary hemostasis include
activated clotting time, activated partial thromboplastin time (PTT), one stage prothrombin time (PT), specific factor analysis, fibrinogen degragation products & d-dimers
what two tests are usually run on the same sample?
PT/PTT
what must occur for either PT or PTT to be prlonged?
the concentration of one or more of the coagulation factors tested must be below about 30% of normal (i.e., they must be markedly reduced before the tests will be abnormal).
what happens if you underfill the citrate tube?
, there will be a relative excess of anticoagulant (ie, the same amount of citrate is in the tube but it is being diluted in less blood). This can result in artificial prolongation of the PT/PTT.
if PT and PTT are both prolonged, what assumptions can you make?
there is a defect in the common pathway OR multiple factors are being affected (both intrinsic and extrinsic are affected)
why are finbrogen degregation products and D-dimers run along with Pt/PTT?
to test for DIC or other thromboembolic dz
rickettsial diseases
ehrliciosis, RMSF, etc. causes TCP, animals may present with petechia or mucosal hemorrhage. TCP may be severe. In chronic form of the dz, will see pancytopenia. Diagnose via antibody titers or PCR
ITP
immune mediated thrombocytopenia: can be idiopathic or secondary. Usually a diagnosis of exclusion.
DIC
disease starts out with excessive coagulation and thrombosis occurring, eventually the animal has bleeding symptoms because of the depletion of platelets and coagulation factors. Because of this, DIC is sometimes called a ‘consumptive coagulopathy’
is DIC a disease?
no, it is a manifestation or end result of other disorders.
effects of DIC on coag test?
prolongagions of PT, PTT, ACT + increased concentrations of D-dimers or FDPs
True or false: the liver can produce coag factors faster than the bone marrow can make platelets
TRUE
what blood smear finding will help support DIC?
schistocytes
how does bone marrow result in TCP
lack of platelet production
myelophthisis
crowding out of normal bone marrow tissue by an abnormal cell type. Commonly myelofibrosis
how many forms of von willebrand dz are there?
three
animals with vWd generally only bleed if
the vWf concentration is below 30% of normal
what is the most common coagulopathy affecting the coagulation proteins
vitamin K antagonism
most common source of vit K antagonism
poisons / rat poison (warfarin like molecules)
what will happen to mycoplasma hemoparasites in EDTA?
they will fall off
appropriate bone marrow responses: the lower the PCV,
the higher the percentage of retics required to consider the anemia regenerative
why may TP be normal with chronic hemorrhage?
liver synthesis will keep up with the blood loss
will you see hypochromasia on a blood film even if MCHC is normal?
yes- MCHC is an average
is iron defiiency anemia regenerative?
yes, it starts off that way, but becomes non regenerative as iron stores are depleted
macrocytosis causes
reticulocytosis, agglutination, hereditary (poodles), breed (normal greyhounds), felv induced dysplasia
what will a coombs test induce?
agglutination if there is antibody bound to RBCs
describe an echinocyte
short, evenly spaced spicules
descreibe an acanthocyte
blunt, unevenly distributed spicules
Dog has increased WBC count, neutrophilia, increased bands, lymphopenia, monocytosis. Hemopathology is normal. What kind of response is this?
inflammatio and stress
Horse has increased WBC count, neutrophilia, lympocytosis.
excitement response
horse is leukopenic- neutropenic. Metamyelocytes are present. Lymphopenia. Smear shows markedly toxic neuts
inflammatory stimulus + stress, with a left shift
mild leukocytosis, lymphocytosis, lymphs are LGLs
could be leukemia or ehrlichia
will acute lymphocytic leukemia show normal morphology?
no
what kind of morphology will chronic lymphocytic leukemia show?
normal or LGL
Leukocytisis, neutropenia, lymphocytosis, circulating blasts, hemopath shows lg immature lymphs.
acute leukemia