Hematology- Anemia
Regenerative Anemia
When a bird suffers from acute blood loss, either externally from a wound, ingestion of a toxin, or internally from a disease process, the body will try to respond to this blood loss. What classification of anemia would best represent this situation?
Answer
A regenerative anemia is when the body recognizes the blood loss and the bone marrow is stimulated to produce new red blood cells. The peripheral blood should reflect an increase of immature red blood cells and reticulocytes.
Reticulocytes
Due to the average life span of the avian red blood cell, it is common to see up to 5% reticulocytes (a polychromatic red blood cell representing the final stage of red cell maturation), in the peripheral blood. What is the average life span of the avian red blood cell?
Answer
28-45 days depending on the species. This is in contrast to dogs and cats, where the average red blood cell lifespan is 120 days
Immature red blood cells vs lymphocytes
When a bird has a strong red blood cell regeneration in the peripheral blood, which white blood cell line may be difficult to distinguish from the immature red blood cells?
Answer
The lymphocyte. The immature red blood cells may vary in size, with a round central nucleus, high nucleus to cytoplasm ratio, and is deeply basophilic. The lymphocyte is a small cell with a round to slightly indented nucleus centrally or eccentrically placed, and scant cytoplasm that is weakly basophilic.
What is hypochromasia and what does it suggest?
Answer
Hypochromasia is when the red blood cells lack their red color. When compared to the mature erythrocyte (RBC), hypochromatic erythrocytes are abnormally pale in color and have cytoplasmic pallor (area of little color). This may reflect iron deficiency, metal toxicities and chronic inflammatory disorders.
The Avian Hematocrit
The avian hematocrit is a component of the CBC (complete blood count. When this tube of blood is spun down, what information may be obtained?
Answer
Once spun the erythrocytes (RBCs) settle to the bottom and the volume percentage of the RBCs can be obtained to determine if the bird is dehydrated or anemic. The plasma is the fluid portion sitting above the RBCs. The color of the fluid, if abnormal, may suggest underlying metabolic dysfunction.
As a raptor responds to anemia, an increase of polychromatic red blood cells will be seen in the blood smear. However, if the polychromatic or immature red blood cells are degenerative in appearance, this may indicate what problem?
Answer
degenerative immature red blood cells may suggest a bone marrow toxicity or degeneration with the response to the anemia fading
When evaluating the blood smear, some of the red blood cells have the appearance of hypochromasia and ballooning. What might this suggest?
Answer
Ballooning red blood cells may be seen with lead toxicity
