Basics of Reading Blood Test Results

Introduction

• Purpose: Understanding how to read blood test results, focusing on CBC (Complete Blood Count) or haematology reports.
• Audience: Aimed at beginners, particularly those entering small animal clinics or veterinary practice.
• Scope: Focus on small animals (cats and dogs), excludes serum biochemistry.

CBC Report Overview

• CBC: Complete Blood Count or Haematology Report.
• Components: Measures red blood cells, white blood cells, and platelets.
• Terminology:
  • Red Blood Cells (RBCs): Erythrocytes
  • White Blood Cells (WBCs): Leukocytes

Red Blood Cells (Erythrocytes) Section

Key Measurements

• Haemoglobin (Hb): Amount of haemoglobin per litre of blood; indicates oxygen-carrying capacity.
• Packed Cell Volume (PCV) or Hematocrit (HCT): Proportion of blood made up of RBCs.
• RBC Count: Number of erythrocytes per unit volume.
• Mean Corpuscular Volume (MCV): Size of erythrocytes.
• Mean Corpuscular Hemoglobin Concentration (MCHC): Color of erythrocytes.

Special Terms

• Reticulocytes: Immature RBCs; indicate body's response to blood loss or anemia.

Conditions

• Erythrocytosis: Increased RBCs; can be due to dehydration or other physiological causes.
• Anemia: Decreased RBCs; can result from destruction, loss, or production issues.
• Cell Classification by MCHC and MCV:
  • Normochromic: Normal color
  • Hypochromic: Less color
  • Hyperchromic: More color
  • Normocytic: Normal size
  • Microcytic: Small size
  • Macrocytic: Large size

White Blood Cells (Leukocytes) Section

Key Types of Leukocytes

• Neutrophils:
  • Increase: Neutrophilia; due to stress, inflammation, or even cancer.
  • Decrease: Neutropenia; caused by severe inflammation or destruction.
• Lymphocytes:
  • Increase: Lymphocytosis; cause by chronic inflammation or stress.
  • Decrease: Lymphopenia; often due to stress.
• Monocytes:
  • Increase: Monocytosis; indicates chronic inflammation.
  • Decrease: Monocytopenia; little clinical significance.
• Eosinophils:
  • Increase: Eosinophilia; related to allergies or parasites.
  • Decrease: Eosinopenia; can be normal or related to stress.
• Basophils: Rare, seen in allergic reactions.

Example Analysis

• Normocytic Normochromic Anemia: Normal size and color, possibly non-regenerative.
• Leukocytosis with Stress Leukogram: Increase in segmented neutrophils, lymphopenia, eosinopenia, and monocytosis.

Additional Considerations

• Greyhounds have naturally higher PCV levels.
• Platelets:
  • Increase: Thrombocytosis
  • Decrease: Thrombocytopenia

Conclusion

• Understanding CBC helps in clinical assessments.
• Resource links and further assistance can be provided for deeper learning.

Further Learning

• Interested in a series or more detailed resources? Let the presenter know if you found the basics series useful and want more content or downloadable resources.

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These notes provide a foundational understanding of reading CBC results, which is essential for veterinary practice, especially in small animal medicine. The information is helpful for students or practitioners entering the field. For more complex cases and diseases, further study and professional consultation are advised.