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83 terms

Hematology & Hemostasis Veterinary Clinical Lab

the study of blood
functions of blood
carries nutrients, oxygen & waste
essential in water & electrolyte balance
controls temperature
functioning of the immune system
components of blood
Plasma - Fluid - clotting factors
Erythrocytes - RBCs
Thrombocytes - Platelets
Leukocytes - WBCs
production of blood cells and platelets
*all blood cells arise from the same pluripotent hematopoietic stem cell
production of erythrocytes/red blood cells
production of thrombocytes/platelets
production of leukocytes/white blood cells
handling of blood sample
collect enough blood for specific test to be run
minimze stress to animal
refrigerate sample
Ethylene Diamine Tetraacetic Acid
combines with calcium insoluably to prevent clotting
does not alter cell morphology
not used for plasma samples
purple top
common needle size for cats/dogs
22 gauge
smaller needle can damage blood cells
plasma ingredients
90% water, 10% dissolved proteins, carbohydrates, vitamins, minerals, antibodies, et al
clotting factor; removing fibrinogen from plasma leaves a fluid called serum.
prevents conversion of prothrombin to thrombin in clotting process
used for plasma samples
sodium, potassium, lithium or ammonium salt
not used for WBC differential because it interferes with staining, clumping
green top
combines insoluably with calcium
used for specific clotting profiles (citrated plasma)
blue top
sample volume factors
quantity needed of serum or plasma
hydration status of animal
normal hydration
PCV= 50%
50% of sample is fluid, 50% is cells
a 10 ml sample will yield 5 ml plasma
elements of blood
1. erythrocytes
2. Neutrophils (granulocyte/leukocyte)
3. Eosinophils (granulocyte/leukocyte)
4. Basophils (granulocyte/leukocyte)
5. Lymphocytes (agranulocyte/leukocyte)
6. Monocytes (agranulocyte/leukocyte)
7. Thrombocytes (fragments of megakaryocyte)
erythrocyte function
transport oxygen from lungs to cells/tissues
immature red blood cell
hemoglobin function
oxygen carrying pigment
protein molecule
iron is most important element in hemoglobin synthesis
reduced number of circulating RBC's = reduced PCV = reduced hemoglobin
buffy coat
thin layer between plasma and RBC's. contains WBC's and platelets
total protein
determines hydration status
found by viewing plasma in refractometer
anemia classification
1. regenerative: bone marrow responds with production, releases immature RBC's, functioning bone marrow
2. nonregenerative: bone marrow dysfunctional, does not respond by producing RBC's
immune-mediated hemolytic anemia, immune mediated RBC destruction, antibodies against host cells, increased erythropoeisis in response to hemolysis
normal sized RBC's
smaller than normal RBC's
lower hemoglobin concentration
larger than normal RBC's
regenerative anemia
increased RBC size due to recticulocytes
less color due to decrease in hemoglobin concentration
normal hemoglobin concentration
mean corpuscular volume MCV
average size of erythrocytes
mean corpuscular hemoglobin MCH
mean wt of hemoglobin contained in average RBC
mean corpuscular hemoglobin concentration MCHC
concentration of hemoglobin in average RBC
ratio of wt of hemoglobin to volume in which it is contained
life span of RBC
cat: 68 days
dog: 110 days
rouleaux formation
coin stacked RBC's
varying sizes of RBC's
varying shapes of RBC's
crenated cells
points on RBC edge
(immune mediated disorders)
clumped cells
can't oxygenate tissues
New Methylene Blue Stain
makes clumped ribosomes visible in reticulocytes
reticulocyte count
percentage of RBC's that are reticulocytes
erythropoietin EPO
kidney hormone that detects hypoxia, stimulating RBC production
stoppage of blood flow
coagulation tests
evaluate specific hemostatic mechanisms:
1. platelet count/estimate
2. whole blood clotting time (2-10 min)
3. buccal mucosa bleeding time (1-5 min, rarely used)
4. fibrinogen degradation product (heated hematocrit vs regular)
5. prothrombin & activated partial prothrombin time (automated)
basophilic stippling
small dark blue bodies within RBC
anemia in cats, lead poisoning in dogs
howell-jolly bodies
basophilic remnants, response to anemia
a granular leukocyte, named for the dark stain of its granules, that brings anticoagulant substances to inflamed tissues
hemobartonella felis
feline infectious anemia
bacteria blood parasite from flea bite
coccoid, rod or ringlike structures near edge of RBC
Heinz bodies
denatured hemoglobin
RBC with nose
normal 5% in cats
found in diabetes, hyperthyroidism, lymphoma
in cats
cat scratch disease in humans
causes inflammation
in dogs (Am Pit Bull Terriers)
protozoal blood parasite
leukocytes functions
important in body's defense system
recognize, respond & remove antigens (abscess)
recognize & remove damaged/dead cells (macrophages)
leukocyte pools
where leukocytes are
blood vessels transport cells between pools
5 types of leukocyte pools
1. proliferation pool (uncirculating) where cells are formed in the bone marrow; immature cells
2. storage pool (uncirculating) where mature cells stored in spleen or bone marrow
3. circulating pool where cells freely move in vasculature; where we get blood sample
4. marginal pool where cells are stuck or rolling along walls of small vessels, not freely circulating
5. tissue pool where cells leave the vessels to enter various body cavities and tissues
decrease in the number of neutrophils
decrease of lymphocytes in blood
decrease of white blood cells (leukocytes)
Increased numbers of neutrophils.
increase in the number of white blood cells (general term)
neoplastic cells in the blood or bone marrow
(new WBC's, in general, trying to compensate for loss of mature WBC's)
leukemoid response
marked leukocytosis (>50,000/microliter) from inflammatory disease, can be mistaken for leukemia
neutrophils morphology
most abundant
segmented nucleus
cytoplasm stains pink with very fine granules
band cell
Immature neutrophil with horseshoe/unsegmented nucleus
neutrophil function
phagocytosis and inflammation
eosinophil morphology
elongated band-shaped, bi-lobed or tri-lobed nucleus
cytoplasm has red/red-orange staining granules
feline: numerous small rod-shaped granules
canine: varying size granules in same cell
eosinophil function
inflammation and allergic conditions
attract histamine
parasitic infections (microfilaria)
basophil morphology
elongated, often coiled nucleus, segmented
cytoplasm stains gray to blue, contains dark blue to purple granules
basophil function
initiate acute inflammatory response
lymphocyte morphology
second most abundant leukocyte
round or slightly indented nucleus
thin rim of blue-stained cytoplasm
larger than nucleated RBC
lymphocyte function
major cell involved in immune response
increase in the number of lymphocytes
seen in very young or scared animals (in conjunction with increased glucose)
lymphoid neoplasia
seen in leukemia, lymphosarcoma
monocyte morphology
largest leukocyte
nucleus is elongated & lobed or kidney bean shaped
abundant cytoplasm, may have vacuoles, phagocytosed particles
stains gray, foamy looking
monocyte function
phagocytosis: engulf and destroy fungi, protozoa, bacteria, intracellular organisms (i.e. blood parasite)
cell mediated immune response: recognize, pick up, & process antigens & bring to lymphocytes
platelets morphology
pieces of cytoplasm of megakaryocyte
vary in shape & size: small oval to star-shaped
may clump on blood smear, esp in cats
platelets function
essential in blood clotting
initiate clotting process
assist in clot retraction
componentes in a CBC
hematocrit tube:
1. PCV (anemia indicator)
2. TP-total protein (hydration status)
3. WBC count (6-19,000 normal)
blood smear:
4. WBC differential (how many of each type)
5. platelet estimate (160-700,000 normal)
6. RBC morphology
unopette function
lyses RBC's to be able to count WBC's
clinical refractometer
reads either total protein, serum protein or plasma protein
WBC count calculation
uses all 9 squares of hemocytometer
read using 100x (low power)
count cells on both sides of slide (2 grids) then divide by 2 for average count
divide average count by dilution & volume factors
expressed in microliters of blood
WBC differential
read with 1000x (oil immersion)
count 100 WBC's, tally each type of WBC
(example: out of 100 WBC's, 5 were leukocytes, therefore leukocytes are 5/100 or 5%)
platelet count
use square #5
read with 400x (high power)
multiply number of platelets counted by 1000 for number of platelets per microliter
done after WBC count
platelet estimate
use blood smear, min 10 microscope fields at 1000x (oil immersion)
8-10 platelets per field is normal, range is 7-21