3 – RBC 1

Question 1

What are the 3 big picture causes of anemia?

Answer 1

1. Blood loss anemia: RBC lost
2. Hemolytic anemia: RBC destroyed
3. NR anemia: RBC not made

Question 2

Regenerative anemia

Answer 2

• Appropriate marrow response to blood loss or hemolysis
• Mild to marked anemia
• Macrocytic, hypochromic
  o Some breeds (ex. poodles) can be macrocytic
• Polychromasia/reticulocytosis

Question 3

Erythropoiesis

Answer 3

• Takes time
• 2-4 days to see retics
• *requires Iron to make Hg

Question 4

Blood loss types (2)

Answer 4

1. External
   a. RBC lost from body
   b. No opportunity for recycling
2. Internal
   a. Recycling
   b. Autotransfusion
   *not always obvious

Question 5

External blood loss: single incident, acute

Answer 5

• Mild to marked anemia
• Normocytic, normochromic
• Nonregenerative
• No change in RBC morphology
• Panhypoproteinemia
• *bone marrow has not had enough time to respond
• “pre-regenerative anemia”

Question 6

External blood loss: single incident, one week later

Answer 6

• Mild to marked anemia
• Macrocytic, hypochromic
• Regeneration
• Polychromasia, macrocytes, nuclear remnants
• Proteins improved

Question 7

Chronic external blood loss

Answer 7

• Mild to marked anemia
• **microcytic, hypochromic
  o Some breeds can be microcytic (Ex. sheba, japenese breeds)
• Inadequately regenerative

Question 8

What is the pathophysiology of chronic external blood loss?

Answer 8

• Iron is lost from body over time
• Iron is not available for Hgb synthesis
• *inadequately regenerative anemia
• Precursors undergo additional divisions=MICROCYTOSIS
• Less hemoglobin=HYPOCHROMASIA
• **DECREASED RBC lifespan
• Thrombocytosis (Fe-deficient)

Question 9

Chronic internal blood loss

Answer 9

• Mild to marked anemia
• Macrocytic, hypochromic
• Regeneration: often robust
• Polychromasia, macrocytes, nuclear remnants
• Proteins WRI

Question 10

RBC with chronic blood loss

Answer 10

• Decreased RBC lifespan
  o More fragile
  o May see keratocytes and schistocytes

Question 11

When do you often see iron-deficiency anemia?

Answer 11

• Chronic external blood loss
  o Parasites
  o GI or GU tract bleeding (ulcers, neoplasia)
  o Hemostatic disorders: hemorrhage
• Inadequate dietary iron: especially neonates (not enough iron in milk)

Question 12

GI and GU tract bleeding is not always obvious

Answer 12

• Hematuria
• Melena
• Hematochezia
• Fecal occult blood
• Fecal float for parasites

Question 13

What are some other indicators we can use to indicate an iron-deficiency anemia?

Answer 13

• Decrease serum [Fe]
• Increased transferring (TIBC)
  o May not see in dogs and cats
• Decreased total body iron stores (ferritin and hemosiderin)

Question 14

Anemia and proteins: external blood loss

Answer 14

• RBC and proteins lost to the body
• Acute: expect panhypoproteinemia
• Chronic: protein often within reference interval (WRI)

Question 15

Anemia and proteins: internal blood loss

Answer 15

• Proteins may NOT be as low as expected

Question 16

Anemia and proteins: hemolysis

Answer 16

• Anemia due to RBC destruction
• Expect proteins to be WRI