Nonregenerative Anemia

Question 1

Non-regenerative anemia:

Anemia due to decreased erythropoiesis:

Bone marrow disease

Answer 1

aplastic anemia

pure red cell aplasia

immune mediated ineffective erythropoiesis

Infectious agents

Spacy occupying lesion

Question 2

Non-regenerative anemia:

Anemia due to decreased erythropoiesis:

Secondary to extramedullary disease

Answer 2

renal failure

anemia of inflammatory disease

Question 3

Non-regenerative anemia

Anemia due to defective erythropoiesis

Answer 3

abnormal hemoglobin synthesis

Acquired and inherited syndromes of defective maturation

Question 4

Failure of Erythropoiesis:

Erythropoietic failure - bone marrow disease

Answer 4

nonregenerative anemia at time of diagnosis - often severe

Normocytic normochromic homogenous

No or very rare reticulocytes in peripheral blood

Question 5

Failure of Erythropoiesis:

Anemia develops slowly but onset of clinical signs may be abrupt

Answer 5

old RBCs are removed at a normal rate, but not replaced by new onew

HCT drops gradually

Clinical signs when Hct is very low

Question 6

Failure of Erythropoiesis:

Syndromes

Answer 6

1. Aplastic anemia - all cell lines in marrow affected
2. Pure red cell aplasia - red cell line only affected at level of erythroid blast forming unit
3. Immune-meidated ineffective erythropoiesis - specific precursor being attacked
4. Space occupying lesion

Question 7

1. Aplastic Anemai / Pancytopenia

Answer 7

• Destruction of multipotential Stem Cells
• Result – Decreased production of all hematopoietic cells
  
  • Neutropenia, thrombocytopenia, and anemia
  • Fatty, acellular bone marrow
  • Presenting signs are often infection or bleeding
    
    • leukopenia and thrombocytopenia occur before anemia
    • RBCs longer life span
• Many possible causes – some below
  
  • Estrogen Toxicity
    
    • dogs – administered estrogens, sertoli cell tumors, ovarian tumors
    • Ferrets – unspayed females, endogenous estrogen toxicosis
  • Drugs
  • Cattle
    
    • ingestion of Bracken fern
  • Infectious agents
  • Idiopathic

Question 8

2. pure Red cell aplasia

Answer 8

markedly decreased to absent concentration of red cell precursors

normal granulopoiesis

normal thrombopoiesis

Severe nonregenerative anemia with normal WBC and platelet concentrations

Question 9

2. pure red cell aplasia:

causes

Answer 9

• Dogs:
  
  • usually immune-meidated destruction of RBC precursors
  • +/- spherocytes and agglutination
• Cats:
  
  • FeLV, subgroup C

Question 10

3. Space occupying lesion in the marrow

Myelofibrosis

Answer 10

abnormal proliferation of stromal cells within the marrow, replacing the hematopoietic tissue

Marrow aspirates are poorly cellular and a core biopsy is needed to make a firm diagnosis

Question 11

3. Space occupying lesion of the Marrow

Myelophthisis

Answer 11

marrow is replaced by an abnormal proiferation of non-hematopoietic cells

Often neoplastic

Aspirates may be poorly cellular or contain many of the abnormal cells

Question 12

4. Anemia of Inflammatory Disease

Answer 12

secondary to extramedullary disease

• Usually mild anemia associated with disease severe enough to have systemic effects
  
  • cancer
  • chronic infection
  • chronic inflammation
• Clinical signs of sustemic inflammatory may include
  
  • fever
  • lethargy
  • inappetence
  • weight loss
• Inflammation blunts the regenerative response to blood loss or hemolytic anemia

Question 13

Anemia of Chronic Renal Failure

Answer 13

• Pathogenesis:
  
  • loss of normal renal tissue reduces Epo synthesis
    
    • inadequate Epo to maintain normal rate of erythropoiesis
  • Decreased lifespan of red cells as uremic acids increase and bleeding may also play a role with disease progression
• Characteristics
  
  • mild to severe
  • severity of anemia correlates to severity of renal disease
  • Normocytic normochromic homogeneous
  • Reticlulocytes usually absent to rare
• Other findings
  
  • weight loss, inappetance, malaise, polyuria/polydipsia, vomiting/diarrhea
  • High concentrations of blood urea nitrogen and creatinine
  • Low urine specific gravity
  • Low normal or decreased calcium

Question 14

Erythrocytosis

Answer 14

increased Hct, increased Hgb, or increased RBC concentration

Increase above the regerence intervals regardless of the cause

Relative vs, absolute

Question 15

Hemoconcentration

Answer 15

increased concentration of blood components because of a decrease in plasma volume

Question 16

Polycythemia

Answer 16

in common usage synonymous with erythrocytosis

Relative or absolute

Question 17

Polycythemia vera

Answer 17

a myeloproliferative disorder with increased production of all circulating cell types

Question 18

Relative erythrocytosis:

Dehydration

Answer 18

• Causing hemoconcentration
  
  • decreased plasma volume causes a relative increase in Hct, RBC number, and Hgb
  • Plasma protein concentrations is increased
  • Dehydration is evident on physical examination
  • Mechanisms:
    
    • water loss due to V/D, water deprivation, sweat, failure to concentrate urine
    • Body cavity effusion
    • edema
  • Treatment involves replacement of fluids and electrolytes and treatment ofthe underlying cause

Question 19

Relative Erythocytosis:

Redistribution or shifiting of RBCs

Answer 19

Catecholamine release with splenic contraction

• The spleen holds many blood cells, and contraction pushes these cells into circulation
• Causes a modest increase in PCV – usually not more than 60%Hct if splenic contraction is the only cause
• Plasma protein is not affected
• The animal does not appear dehydrated
• Transient
• No clinical significance