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122 Cards in this Set
- Front
- Back
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What are the functions of RBCs?
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transport O2 to tissues
synthesize hemoglobin (Hb) |
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Under what conditions is erythropoietin produced?
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produced by kidney in response to hypoxia
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What are the effects of erythropoietin?
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↑ # of developing cells
↓ maturation time ↑ Hb synthesis w/in individual cells ↑ release of reticulocytes from BM |
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What is the functional abnormality of methemoglobin?
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cannot carry O2 b/c iron is oxidized (Fe3+)
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What is the comparative RBC lifespan in dogs, horses, cats, cows?
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cat < dog < horse < cow
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What does the PCV/Hct measure & which is more accurate?
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% of whole blood that is RBCs
PCV considered more accurate |
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What factors can artifically increase measured Hb concentration?
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lipemia, Heinz bodies, WBC > 50,000/µl, hyperbilirubinemia
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What factors can cause errors in measured RBC count?
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species RBC size variation, counting of large platelets, not counting small RBCs (microcytes), or agglutination
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What is MCV?
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mean corpuscular volume = average RBC volume (size)
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What is MCHC?
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mean corpuscular hemoglobin concentration = average conc. of Hb per RBC volume
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What is RDW?
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random distribution of RBC weight: distribution of RBC's based on their volume (size)
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What does the plasma protein:fibrinogen ratio determine & in what species is it commonly measured?
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used to determine cause of ↑ PP in LARGE ANIMALS
≥ 15 = dehydration ≤ 10 = inflammation |
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What is the name for an
a) increase b) decrease in MCV? |
a. macrocytosis
b. microcytosis |
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What is the name for an
a) increase b) decrease in MCHC? |
a. hyperchromasia
b. hypochromasia |
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What is the name for any abnormally shaped RBC?
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poikilocyte
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What is an acanthocyte & with what disorders is it associated?
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spiculated RBC w/ single or multiple, irregular, blunt, rounded projections
liver dz (more in cats), microangiopathy, HSA |
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What is an keratocyte & with what disorders is it associated?
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spiculated RBC w/ 1 or 2 pointed projections
Fe deficiency, liver disorders |
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What is an echinocyte & with what disorders is it associated?
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spiculated RBC w/ numerous short, evenly shaped surface projections
snake bite envenomation, crenation, dehydration |
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What is an spherocyte & with what disorders is it associated?
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small dense RBC lacking central pallor
IMHA, Heinz body anemia, transfusion |
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What is an schistocyte & with what disorders is it associated?
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fragmented RBC
DIC, microangiopathy |
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What is an eccentrocyte & with what conditions is it associated?
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RBC w/ condensed Hb in one area of cell
oxidative damage to Hb |
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What is a nucleated RBC & with what conditions is it associated?
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Immature RBC w/ a nucleus in peripheral blood
intense BM stimulation, BM injury, after splenectomy, lead poisoning |
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What is a Howell Jolly body & with what conditions is it associated?
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Basophilic nuclear remnants usually near edge of RBC (Romanowsky stains)
accelerated RBC production |
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What is a Heinz body & with what conditions is it associated?
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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 |
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What is basophilic stippling & with what conditions is it associated?
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RBCs containing residual RNA, appear as multiple, small blue dots w/ Romanowsky stains
ruminants: regeneration other species: lead poisoning |
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What is agglutination & with what conditions is it associated?
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Grape like aggregation of RBCs that will NOT disperse w/ saline dilution
IMHA |
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What is Rouleaux formation & with what conditions is it associated?
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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 |
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What is crenation & with what conditions is it associated?
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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) |
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What are 4 parasites that may be found w/in RBCs?
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Anaplasma
Babesia Mycoplasma Ehrlichia |
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What is polycythemia?
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increase RBC count, PCV, Hb
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What is relative polycythemia?
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increased PCV, & Hb with normal total RBC mass
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What are the 2 main causes of relative polycythemia?
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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 |
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What is absolute polycythemia?
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increased PCV & Hb w/ ↑ in total RBC mass d/t ↑ erythropoiesis (less common than relative)
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What is the cause of primary absolute polycythemia?
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bone marrow disorder --> uncontrolled RBC production (RARE)
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What are the 2 causes of secondary absolute polycythemia?
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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 |
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What is anemia?
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↓ RBC count, PCV, & Hb
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What 3 schemes are used to classify an anemia?
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RBC indices (MCV, MCHC)
BM response (regenerative vs. non-regenerative) underlying cause |
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What are the 3 main underlying causes of anemia, what are the associated changes in plasma protein, & how would you diagnosis each?
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↓ 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 |
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What are some causes of microcytosis?
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iron deficiency
PSS normal in Akitas, Japanese Shiba implies abnormal Hb synthesis --> smaller cells |
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What are some causes of macrocytosis?
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regeneration
FeLV may be normal in Poodles false (d/t agglutination) assoc. w/ increased erythropoeisis --> release of retics (larger than mature RBCs) |
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What are some causes of hypochromasia?
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Fe deficiency
reticulocytosis |
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What are some causes of hyperchromasia?
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hemolysis (true hyperchromic cells don’t exist)
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What is the most common type of anemia based on RBC indices?
Is it usually regenerative or non-regenerative? |
normocytic normochromic
usually non-regenerative |
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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 |
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ddx for macrocytic hypochromic anemia
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regenerative anemia (reticulocytosis)
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ddx for macrocytic normochromic anemia
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FeLV (altered RBC maturation), may be normal in miniature & toy poodles
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What signs are evidence of regeneration on a blood smear?
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reticulocytosis
basophilic stippling (bovine) macrocytosis (horse) Howell Jolly bodies anisocytosis |
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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) |
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What are the 2 major causes of regenerative anemia?
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blood loss
hemolysis |
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What are the early pre-regenerative responses during acute blood loss?
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↑ blood volume: shift ECF to IV space
↑ RBCs: splenic contraction |
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What other hemogram or chemistry abnormalities are associated w/ blood loss anemia?
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decreased plasma protein
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What other hemogram or chemistry abnormalities are associated w/ hemolytic anemia?
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normal or ↑ PP hyperbilirubinemia hemoglobinemia
hemoglobinuria RBC morphology (spherocytes, parasites, Heinz bodies) |
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What is extravascular hemolysis & what is a commonly associated serum chemistry change?
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abnormal RBCs phagocytosed by MPS in spleen & liver (more common)
hyperbilirubinemia usually present |
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What are some causes of extravascular hemolysis?
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IMHA, oxidative damage, intrinsic RBC defects, parasites
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What RBC morphologic changes are associated w/ IMHA?
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anisocytosis, polychromasia (regeneration), agglutination, spherocytes, ghost cells, ↑ MCV (d/t retics & agglutination)
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What is the Coomb's test?
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used to help dx IMHA
detects Ab &/or complement bound to patient’s RBCs positive ≠ 1º IMHA |
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What RBC morphologic changes are associated w/ oxidative hemolytic anemia?
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Heinz bodies, eccentrocytes
methemoglobinemia also called Heinz body hemolytic anemia |
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What are the features assoc. w/ pyruvate kinase deficiency?
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PK needed for ATP production (needed to maintain RBC mems)
consistent hemolysis, severe anemia w/ marked regeneration survival < 3-5 yrs congenital in Beagles, Basenjis |
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What are the features assoc. w/ phosphofructokinase deficiency?
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PFK needed for ATP production (needed to maintain RBC mems)
hemolysis induced by alkalosis (ex. stress, exercise-induced hyperventilation) English Spring Spaniels |
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What is intravascular hemolysis & what are 2 prominent features that help to dx it?
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RBCs lysed w/in bloodstream: poorer px
hemoglobinemia, hemoglobinuria |
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What are some causes of intravascular hemolysis?
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complement mediated, bacterial toxins, parasites, hereditary, chemicals/toxins
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What are some causes of fragmentation of RBCs (subset of intravascular hemolysis)?
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microangiopathy: abnormal small vessels (see acanthocytes, schistocytes)
ex. HSA, vasculitis DIC: fibrin deposited in vessels (schistocytes) |
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What CBC findings are consistent w/ nonregenerative anemia?
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no retics
no polychromasia variable anisocytosis N to ↑ nRBCs N to variable MCV & MCHC hx: chronic |
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What is the main defect associated w/ non-regenerative anemias?
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decreased erythropoiesis = hypoproliferative BM d/t inadequate # of precursors or inadequate stimulus
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What are some causes of non-regenerative anemia?
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Fe deficiency
ACD lack of EPO BM damage myelophthisis |
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What are some causes of iron deficiency anemia?
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chronic blood loss: parasites, ulcers (most common)
dietary deficiency: young animals (uncommon) malabsorption: intestinal dz |
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What lab findings are consistent w/ iron deficiency anemia?
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microcytic hypochromic anemia
non-regenerative ↓ serum iron ↓ bone marrow iron stores ↓ ferritin (storage form of iron) thrombocytosis: megakaryocytes respond to EPO |
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What is the most common anemia of domestic animals?
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anemia of chronic dz
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What lab findings are consistent w/ anemia of chronic dz?
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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 |
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How could you differentiate non-regenerative anemia as being caused by Fe defeciency or ACD?
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give patient some iron
improvement = Fe deficiency no improvement = ACD |
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What are some examples of multifactoral anemias?
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neoplasia
chronic renal failure endocrine disorders: hyperestrogenism (ferrets, dogs), hypothyroidism, Addison's FelV |
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What is aplastic anemia & what are some causes?
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depletion of all 3 cell lines in blood & BM
causes: estrogen, infections (Ehrlichia, FelV), drugs, plants, radiation |
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What are 3 main underlying causes of thrombocytopenia?
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increased destruction (common)
increased consumption or sequestration decreased production |
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What are the functions of platelets?
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plug endothelial lesions, clot formation, release soluble mediators
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How do platelets form & what controls their production?
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produced by “flaking off” from megakaryocytes
thrombopoietin controls production |
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What are common causes of thrombocytopenia d/t increased destruction?
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immune mediated
1º (autoimmune): Abs against self Ag on megakaryocytes &/or platelets 2º: Abs against non-self Ag on platelet surface |
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What are common causes of thrombocytopenia d/t increased consumption or sequestration?
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DIC: most common
sequestration (ex. spleen): transient, not common massive hemorrhage: would take huge blood loss |
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What are common causes of thrombocytopenia d/t decreased production?
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marrow suppression d/t drugs, toxins, infectious agents, neoplasia, etc.
↓ platelets w/ ↓ WBCs &/or ↓ RBCs |
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What are some characteristics of platelet regeneration?
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large platelets
↑ MPV BM: megakaryocytic hyperplasia (↑ # of megakaryocytes) |
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What are 3 main categories of thrombocytosis?
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physiologic: common
reactive: common myeloproliferative/neoplastic: rare |
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What are causes of physiologic thrombocytosis?
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transient mobilization: minutes to hours (d/t splenic contraction)
exercise & epinephrine |
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What are causes of reactive thrombocytosis?
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↑ production by BM d/t:
thrombopoietin erythropoietin (anemia) inflammation |
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What is Evans' syndrome?
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concurrent IMHA & IMTP
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In what species are lymphocytes usually more prevalent in peripheral blood than neutrophils?
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cattle
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What is meant by the term left shift?
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indicates presence of immature granulocytes (usually neutrophils) in blood
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What is a regenerative left shift?
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leukocytosis in which mature neutrophils outnumber immature neutrophils
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What is a degenerative left shift?
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immature neutrophils outnumber mature neutrophils
indicates excessive demand &/or inadequate supply (more guarded px) |
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What is a leukemoid rxn?
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very high neutrophil count w/ a severe, but orderly left shift
indicates severe inflammation but a responding bone marrow |
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What are the CBC changes consistent w/ leukemia?
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presence of neoplastic hematopoietic cells in circulation
leukocytosis; immature forms: often 1 stage overrepresented; disorderly maturation |
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What are the functions of neutrophils?
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chemotaxis: cell migration to site of inflammation
engulfment/killing: release of granule contents (enzymes that kill bacteria) |
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What are band neutrophils?
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immature neutrophils that has a nucleus w/ parallel sides
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What are hypersegmented neutrophils?
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neutrophils w/ 5 or more distinct nuclear lobes
indication of prolonged transit time (glucocorticoids) |
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What are toxic neutrophils & what 3 morphologic features do they possess?
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indicate inflammation (↑ demand for neutrophils)
↑ basophilia of cytoplasm, vacuolated (foamy) cytoplasm, Dohle bodies (bluish angular cytoplasmic inclusions |
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What are the 3 neutrophil pools found in the bone marrow?
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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 |
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What are the 2 neutrophil pools found in blood?
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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 |
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What is the comparative order of species in terms of intensity of immune response to inflammation: cats, dogs, horses, cows?
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dog > cat > horse > cow
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What WBC characteristics are consistent w/ inflammation w/ a mild to moderate tissue demand (ex. abscess?)
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neutrophilia +/- left shift, monocytosis, toxic neutrophils may be seen
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What WBC characteristics are consistent w/ inflammation w/ continued tussue demand (ex. pyometra?)
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neutrophilia w/ regenerative left shift & toxic neutrophils, monocytosis
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What WBC characteristics are consistent w/ inflammation w/ an excessive tissue demand (ex. Salmonellosis?)
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neutropenia, degenerative left shift, toxic neutrophils
insufficient storage cells for demand & BM has not had time to respond |
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What WBC changes are expected in cattle w/
a. subacute or chronic inflammation? b. inflammation w/ moderate tissue demand? |
a. neutrophilia, esp. w/ a left shift
b. normal neutrophil count or neutropenia, left shift, & toxic neutrophils |
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What are some causes of neutropenia?
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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 |
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What is leukocyte adhesion deficiency?
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WBCs can’t migrate from circulation --> neutrophilic leukocytosis
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What is Pelger-Huet Anomaly?
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hyposegmented nuclei of neutrophils, eosinophils, basophils
normal function concern is not to mistake for a left shift inflammatory process |
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What is Chediak-Higashi syndrome?
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large granules in neutrophils, eosinophils, basophils
defective microbiocidal activity defective platelets --> ↑ bleeding times |
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What is cyclic neutropenia of Collies?
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stem cell defect --> cyclic myelopoiesis every 11 days
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What diseases are assoc. w/ acquired functional abnormalities of neutrophils?
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diabetes mellitus (if poorly controlled)
vaccines zinc deficiency (dogs) selenium deficiency (cattle) drugs (steroids, NSAIDs, some ABs) |
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What is physiologic leukocytosis (epinephrine response)?
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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 |
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What is corticosteroid induced leukocytosis (stress response)?
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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 |
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What are some causes of lymphocytosis?
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epinephrine response
immunological stimulation infectious dz: Ehrlichia, bovine leukemia virus lymphocytic leukemia Addison's: stressed dog lacking a stress response normal in cows, swine |
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What are some causes of lymphopenia?
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stress response
acute infections (esp. viral) loss of lymph radiation/chemo immunodeficiency (less common) |
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What are the functions of monocytes?
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phagocytosis & degradation of ingested material
present antigen to initiate lymphocyte responses |
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What are some causes of monocytosis?
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think CHRONIC INFLAMMATION 1st!: tissue destruction, necrosis, intracellular or fungal organisms
stress response: esp. in dogs immune mediated disorders |
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What are the functions of eosinophils?
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regulation of type I (immediate) & type III (delayed) hypersensitivity rxns
antiparasitic properties bacterial phagocytosis (less so than neutrophils) activation of plasminogen |
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What are some causes of eosinophilia?
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parasites
hypersensitivity rxns hypereosinophilic syndromes neoplasia |
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What are the functions of basophils?
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hypersensitivity (histamine release)
follow eosinophils possible cytotoxic effects against tumor cells possibly anti-parasitic |
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What are some causes of basophilia?
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w/ eosinophilia: parasites, hypersensitivity, neoplasia
rare to have w/o eosinophilia: basophilic leukemia |
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What is leukemia?
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neoplastic cells of BM origin in circulation --> leukocytosis
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What is lymphoma?
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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 |
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What is myeloproliferative dz?
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proliferation of granulocytic, megakaryocytic, erythrocytic, &/or stromal CT cells in BM
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What are myelodysplastic syndromes?
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ineffective hematopoiesis w/ resultant peripheral blood cytopenias (ex. FeLV)
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What are some causes of mastocytosis?
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malignant disseminated mast cell neoplasm
immediate type hypersensitivity rxn |
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How is leukemia classified?
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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 |
