Advanced Small Animal Hematology Flashcards
When evaluating the hematopoietic system, what are three things we always need?
- History
- Physical exam with lymph node palpation
- Complete blood count (CBC)
Whole blood is made up of…
- Plasma
- Liquid component: water, proteins, sugars, lipids, electrolytes - Cells
- Erythrocytes
- Leukocytes
- Thrombocytes
In erythrocyte morphology, what do we look for? (6)
- Arrangement
- Color
- Size
- Shape
- Number
- Unique features
- Nuclei, inclusions, parasites
What do the number of erythrocytes tell us? (2) Color? (2)
- Number
- Anemia: decreased RBC
- Polycythemia: increased RBC - Color
- Hypochromasia: decreased blue staining due to decreased iron content
- Polychromasia: multiple colors in population of RBCs due to presence of young bluer cells
Hypochromasia is what?
Refers to the appearance of increased central pallor with a thin rim of cytoplasm
- Usually due to low iron anemia
Polychromasia is usually associated with what?
Regenerative anemia. Young RBCs are bluer due to RNA
What do the size of erythrocytes tell us? Arrangement?
- Size
- Macrocytosis: enlarged due to young red cells
- Microcytosis: Small due to decreased Hgb content
- Anisocytosis: Variable size in population - Arrangement
- Rouleaux: “stacking of red cells” dispersed with saline
- Agglutination: clumping of red cells due to antibody attachment
What is happening with the RBCs?
Macrocytosis
Enlarged due to young red cells
Rouleaux vs Agglutination
Rouleaux is stacking of RBCs while agglutination is clumping of RBCs
Poikilcytes
Erythrocytes with abnormal shape for the species at hand.
- Some poikilocytes have fairly specific diagnostic significance, while other forms are very non-specific.
Spherocyte
Red cells which have assumed the form of a sphere rather than the normal discoid shape
- Loss of central pallor
- Often due to spleen removing damaged areas
Schistocyte
Or red cell fragments, are generally taken to reflect mechanical injury to erythrocytes
- Tumor of spleen or liver are common causes
Nucleated RBCs can be due to… (5)
- Bone marrow injury
- Lead poisoning
- Acute myeloid leukemia & myelodysplasia
- Abnormal splenic function
- Physiologic
- Mini schnauzers, poodles, and daschunds can have smaller numbers of nRBCs in health
- Regenerative response to anemia
Reticulocytes
Slightly immature, anucleated red cells that contain RNA.
- RNA that binds to basic dyes, may be sufficient to impart a blue-gray tint called polychromatophilia
- New Methylene Blue is a special stain to ID reticulocytes
Echinocytes are ___ red cells that have changed from a disc shape to spheres covered with short, ___ pointed projections.
Common causes:
- Crenated
- Sharp
- Causes:
- Slow drying of the smear
- Aging of blood
- EDTA
Water artifact (2)
- Water contamination of stain or slide
- Causes “bubble” appearance
Platelets
Purpose:
Produced where?
- Purpose:
- First defense against hemorrhage - Produced by megakaryocytes in bone marrow
Thrombocytopenia definition
Too few platelets
Thrombocytosis definition
Increased numbers of platelets
Leukopenia definition
Too few white blood cells
Neutropenia definition
Too few neutrophils
Leukocytosis definition
An increase in the number of circulating white blood cells, often due to infection or inflammation
Band cell is…
Morphology
- Immature granulocyte
- Morphology:
- Nucleus is curved to “U” shape
- Once waist pinches down 1/3 or more compared to nucleus ends, then it’s classified as segmented.
Toxic changes in neutrophils are ___ abnormalities acquired during ___ under conditions that intensely ___ neutrophil production & ___ the maturation time in marrow.
They will have less condensed ____ than their normal counterparts & ___ cytoplasm due to retention of ___ RNA.
- Morphologic
- Maturation
- Stimulate
- Shorten
- Chromatin
- Bluer
- Ribosomal
