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Diagnostic Test🐕 Dogs🐈 Catshematologic immune

Hematocrit (HCT) / Packed Cell Volume (PCV)

🗣️ Pronounced:hee-MAT-oh-krit / P-C-V
In One Sentence (Plain English)

The percentage of whole blood volume made up of red blood cells, providing the primary measure of anemia and hydration status.

Editorial Status: Verified from peer-reviewed veterinary sources (v1.0)
Updated: 2026-01-15

💬 In Plain English

Packed Cell Volume (PCV) and Hematocrit (HCT) measure what percentage of your pet’s blood is made of red blood cells. A tiny glass capillary tube is filled with blood and spun in a high-speed centrifuge for 3 minutes, packing the heavy red blood cells to the bottom. In healthy dogs, red cells make up roughly 37% to 55% of blood; in cats, roughly 30% to 45%. If this number drops, your pet is anemic (from bleeding, immune destruction, or bone marrow failure). If it shoots abnormally high, your pet is severely dehydrated.

🔬 Clinical & Technical Depth

For Vets & Technicians

Formal Clinical Definition

Volume percentage of erythrocytes in whole blood. PCV is measured manually via microhematocrit centrifugation; HCT is mathematically calculated by automated hematology analyzers (HCT = [RBC count × MCV] / 10).

Why Veterinarians Use It

Veterinarians use PCV/TP as a rapid, 3-minute bedside test during emergency triage, surgery monitoring, and anemia investigations.

Clinical Context Encountered

Performed routinely in emergency rooms, ICUs, and pre-surgery holding areas using a drop of blood.

Clinical Reference Guide (Diagnostic Test)

Sample Required
Patient Preparation
🚨 Red Flag Warnings (When to Contact an Emergency Vet)
  • •A PCV dropping below 15–18% causes critical cellular hypoxia: lethargy, collapse, pale gums, and rapid breathing require immediate blood transfusion therapy.

❓ Questions to Ask Your Veterinarian

Take these actionable questions with you to your next clinic visit or appointment:

  • 1What was my pet’s exact PCV percentage and Total Protein (TP) number?
  • 2Is the anemia regenerative (bone marrow releasing young reticulocytes) or non-regenerative?
  • 3Has the PCV dropped low enough (<15–20%) to warrant a blood transfusion?

Academic & Clinical References

  • ASVCP Guidelines for Bedside Emergency Hematocrit and Total Solids Testing
    Organization: American Society for Veterinary Clinical Pathology (ASVCP) • Accessed: 2026-01-10
    https://www.asvcp.org