Liquid part of blood without clotting factors or fibrinogen (red top or tiger top), used for total proteins
Liquid part of blood with clotting factors and fibrinogen still inside.
Lavender top (anticoagulant), used for total solids and CBC
Separated blood (MHC) is made up of...
Plasma: 55% of blood. 91% water, 7% proteins, 2% nutrients, hormones and electrolytes.
Cellular portion: 45% of blood. Includes buffy coat (WBC, platelets) and RBCs.
Considerations of internal vs external laboratories
time, equipment, personnel, cost, quality control, stability of sample, hours of operation, veterinary commercial laboratory
Packed Cell Volume (PCV)
fraction of total blood volume in a microhematocrit tube that is occupied by red blood cells. (WBC and platelets are located in the buffy coat). 40 is average(-ish)
Plasma protein concentration
determined on a refractometer. Should be clear (can be icteric, hemolyzed, lipemic).
indicates excess bilirubin.
With a normal hematocrit, can indicate liver disease.
with low hematocrit, indicates an increased destruction of RBCs
indicates presence of free hemoglobin.
True hemoglobinemia - intravascular hemolysis, will not see RBCs under microscope
Secondary to sample collection - rough handling, fragile cells, lipemia, prolonged storage, spun too early
Indicates presence of chylomicrons and very low density lipoproteins (lipemia)
can be postprandial (after eating), caused by diseases (endocrinopathies like diabetes, protein-losing nephropathy, obesity, cholestasis, or starvation) or caused by heredity (idiopathic hyperlipidemia in Schnauzers, lipoprotein lipase deficiency in cats)
mean cell hemoglobin, average hemoglobin per cell.
mean cell hemoglobin concentration, amount of hemoglobin relative to other stuff
hematocrit--percent red blood cells
mean cell volume. Average size.
total and differential leukocyte concentrations
total is how many WBC, overall. Differential is how many types of each WBC.
Presence of too many indicates regenerative anemia
maturation begins in bone marrow, completed in blood and spleen.
Reticulocyte percentage (reticulocyte count)
Count 1000 RBC, categorize as reticulocytes or normal. Reticulocytes/1000 x 100
RP wnl nonregenerative
corrected and absolute reticulocyte count
Reticulocyte count must be corrected for degree of anemia present.
HCT - corrected retic count = HCT/mean normal HCT for species x raw retic count in percent
RBC - absolute retic count (per microliter) = RBC count (per milliliter) x raw retic count (fraction). Determined directly by flow cytometry
dogs and cats should have 0-60,000 cells/uL
cows should have none, horses don't even have reticulocytes.
0-10,000 cells per microliter
nonregenerative anemia to very poor regeneration
10,000 - 60,000 cells per microliter
nonregerative to poorly regenerative anemia
60,000 - 200,000 cells per microliter
regenerative anemia to mild or moderate output
200,000 - 500,000 cells per microliter
maximal regenerative response
complete blood count. Summarizes and organizes test results. Provides a framework for interpretation
D/C/H/C reticulocyte concentration
RBC life span
RBC central pallor
reticulocyte concentration: D>Ct. H, Cw = 0
RBC concentration: H>Ct>/= D = Cw
RBC life span: H=Cw>D>Ct
RBC diameter: D>Ct>/= H=Cw
RBC volume: D>Cw>H=Ct
RBC central pallor: D>Cw>Ct>H
Principal component of erythrocytes
transports O2 (50x more than plasma)
Carries more with more hemoglobin, higher partial pressure, higher hemoglobin affinity for O2.
Transports CO2 from tissues to lungs, assists in acid/base.
complete and detailed record of the findings in a thorough examination of the blood. Includes numbers, proportions, morphology, hematocrit and total proteins
hematocrit. Percentage of blood volume filled by erythrocytes. Measure of O2 carrying capacity of blood.
packed cell volume. Measure by centrifugation, measures % of RBC in blood.
blood hemoglobin content. Grams hemoglobin per 100 ml (1 dL) of blood.
more direct measure of O2 carrying capacity than HCT or RBC
red blood cell count. Number of erythrocytes per unit volume of blood (cells per microliter). Used to calculate MCH and MCV
mean cell volume. Volume per average erythrocyte expressed in fL (femtoliters) (femto = 1 quadrillionth, or 10-15)
Traditionally calculated or automated hematology analyzers.
MCV = (PCV/RBC) x 10
varying cell size
size appropriate for the species (and age)
mean cell hemoglobin. Quantity of hemoglobin per average erythrocyte expressed in picograms (pg)
calculated from Hgb and RBC
MCH (pg) = (Hgb/RBC) x 10
MCHC - (Hgb/HCT) x 100
mean cell hemoglobin concentration. Cellular hemoglobin concentration per average erythrocyte expressed as grams per hemoglobin per 100 mL of erythrocytes (g/dL)
Calculated from Hgb and HCT
Increases with hemolyzsis, heinz bodies, cryoproteins or lipemia
decreases with regenerative anemia, hypernatremia or chronic iron deficiency.
decreased MCHC. Increased central pallor
increased MCHC, decreased central pallor
MCHC wnl. Appropriate level of central pallor for the species.
red cell distribution width. Calculated value usually expressed as a percentage. Reflects amount of variation in erythrocyte volume. Measure of anisocytosis (increased number of reticulocytes will cause RDW).
nucleated red blood cells. Counted by hematology analyzers as WBCs, so WBC count must be corrected for nRBCs in circulation.
Corrected WBC count
(measured WBC count x 100) / (100 + nRBC)
Immature anucleated RBCs. Released to blood in increased numbers as a response to anemia caused by hemolysis or blood loss in most species (not in horses).
Aggregates of erythrocytes grouped like a stack of coins. Depends on erythrocytes (more deformable with less surface charge) and plasma (high molecular weight proteins)
Normal in horse, sometimes in cat
aggregation of erythrocytes in clusters. Caused by immunoglobulins bound to erythrocyte surface
Happens in immune-mediated hemolytic anemia, tested for with saline test.
Saline agglutination test
screens for immune-mediated hemolytic anemia. Agglutination is a positive result (except a little in cat).
Mix whole blood with saline 1:1 on a slide, look for agglutination.
variable colors of RBC on a slide (reticulocytes)
erythrocytes after loss of hemoglobin.
immature RBC that stains bluish-red due to presence of both hemoglobin and RNA
variation in erythrocyte diameter. Seen in regenerative anemia or post transfusion
increased number of erythrocytes with small diameter. Decreased iron or microcytic anemia
increased number of erythrocytes with larger than normal diameter
general term to describe presence of abnormally shaped erythrocytes. Normal in goats and calves, can indicate liver disease, oxidative injury, chemo drug (doxorubracin), DIC (deceminated intravascular coagulation)
Erythrocyte fragments with pointed extremities (tiny bits).
Caval syndrome, when heartworms back up into vena cavae. Can also be caused by DIC
blister cell. Erythrocytes containing one or more intact holes.
Increase in fibrin
Erythrocyte with ruptured holes. "helmet cells". Caused by trauma, endotoxemia, excess fibrin.
Erythrocytes with irregularly spaced and variably sized spicules. "spur cells"
Spiculated erythrocytes, evenly spaced and of similar size. "burr cells".
smaller diameter than normal erythrocytes, lacking central pallor. Indicate immune-mediated hemolytic anemia.
elliptical or oval erythrocytes. Generally flat. Seen in nonmammals or camelidae family.
teardrop shaped erythrocytes with single elongated or pointed extremity.
spindle-shaped erythrocyte. "sickle cell"
bulk of erythrocyte is shifted to one side. Hemoglobin is localized to one part of cell. Visibly pale in hemoglobin-poor area.
Thin, hypochromic erythrocytes with increased membrane-to-volume ratios (more border than inside). Triconcave, central bar of hemoglobin. Also called condocytes, or target cells.
cup shaped erythrocyte with oval or elongated areas of central pallor.
large aggregates of oxidized precipitated hgb that show primarily in methylene blue stain (Howell-Jolly are the blue in wright's)
blue-staining punctate inclusions in reticulocytes (tiny blue dots). Can indicate lead poisoning.
small spherical nuclear remnants that stain in Wright's stain (Heinz bodies do not)
iron positive inclusions in erythrocytes. Also called siderocytes or "pappenheimer bodies"
Infectious agents of RBC for feline, canine, bovine
feline: mycoplasma haemofelis (hemobartonella) and cytauxzoon felis
Coombs: detects presents of antibody against RBCs. Not definitive--only negative is definitive.
Coggins: detects antibodies against EIA. Definitive.
Causes of nonregenerative anemia
1.reduced erythropoiesis (kidneys)
2.chronic diseases-most common in domestic animals, many reasons.
3. cytoxic bone marrow damage
4. Myeloproliferative disorder
chronic infection causing nonregenerative anemia
most common in domestic animals. Can be chronic infections, noninfectious disorders (neoplasia, chronic inflammatory disorders). Lab=mild to moderate nonregnerative normocytic, chronic inflammatory leukogram, mature neutrophilia, lymphocytosis or monocytosis