Cat CBC (Complete Blood Count) Explained: What Every Pet Owner Should Know
Understanding your cat's CBC (Complete Blood Count) results can seem overwhelming, but it's one of the most important diagnostic tools veterinarians use. This guide breaks down every component of the CBC and what the results mean for your cat's health.
What is a Complete Blood Count (CBC) for Cats?
A CBC is a comprehensive blood test that evaluates the different types of cells in your cat's blood. It provides valuable information about your cat's immune system, oxygen-carrying capacity, and ability to clot blood. This test is essential for diagnosing many conditions and monitoring your cat's overall health.
Key Components of a Cat CBC:
- Red Blood Cells (RBC): Carry oxygen throughout the body
- White Blood Cells (WBC): Fight infection and disease
- Platelets: Help blood clot to prevent bleeding
- Hematocrit (PCV): Percentage of blood volume that is red blood cells
- Hemoglobin: Protein in red blood cells that carries oxygen
Normal CBC Ranges for Cats
Typical Normal Ranges for Adult Cats:
- • RBC: 5.0–10.0 million cells/μL
- • WBC: 5,500–19,500 cells/μL
- • Platelets: 300,000–800,000 cells/μL
- • Hematocrit (PCV): 30–45%
- • Hemoglobin: 8–15 g/dL
*Ranges may vary slightly between laboratories and with age
Understanding Red Blood Cell Parameters
Low Red Blood Cell Count (Anemia): May be caused by blood loss (trauma, parasites, gastrointestinal bleeding), chronic kidney disease, feline leukemia virus (FeLV) or immunodeficiency virus (FIV), autoimmune hemolytic anemia, or cancer/bone marrow disease.
High Red Blood Cell Count (Polycythemia): Usually due to dehydration, but can also result from heart or lung disease, kidney tumors, or living at high altitude.
White Blood Cell Differential in Cats
The white blood cell differential breaks down the different types of immune cells:
Normal WBC Differential for Cats:
- Neutrophils: 35–75% (fight bacterial infections)
- Lymphocytes: 20–55% (handle viral infections and immunity)
- Monocytes: 1–4% (clean up debris and fight some infections)
- Eosinophils: 2–12% (respond to allergies and parasites)
- Basophils: 0–1% (involved in allergic reactions)
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Try VetLens FreeCommon Abnormalities and Their Meanings
High White Blood Cell Count: May be caused by bacterial infections, stress or excitement, inflammatory conditions, certain medications (corticosteroids), or less commonly, leukemia.
Low White Blood Cell Count:
- • Viral infections (FeLV, FIV, panleukopenia)
- • Bone marrow suppression
- • Overwhelming bacterial infections
- • Certain medications or toxins
- • Autoimmune diseases
Platelet Count in Cats
Platelets are essential for proper blood clotting:
- Low Platelet Count: May indicate immune-mediated destruction, bone marrow disease, or blood loss
- High Platelet Count: Can occur with inflammation, cancer, or after blood loss
- Clumped Platelets: May artificially lower the count; manual review often needed
Age-Related Changes in Cat CBC
Kittens (Under 1 Year): Have higher lymphocyte percentages and lower neutrophil percentages than adults, and may have slightly different normal ranges.
Senior Cats (7+ Years): May have mild decreases in red blood cell count, require increased monitoring, and are more susceptible to chronic diseases affecting blood values.
When CBC Testing is Recommended
- • Annual wellness examinations
- • Pre-surgical evaluations
- • When cats show signs of illness (lethargy, poor appetite, weight loss)
- • Monitoring chronic diseases
- • Following up on previous abnormal results
- • Evaluating response to treatment
Important Note: A CBC provides valuable information, but results must be interpreted alongside your cat's clinical signs, physical examination findings, and other diagnostic tests. Never rely on CBC results alone for diagnosis.
Get Your Cat's CBC Results Explained
Upload your cat's bloodwork into VetLens and receive:
- ✓ Clear explanations of every CBC component
- ✓ Context about what abnormal values might mean
- ✓ Tracking of trends over time
- ✓ Personalized insights based on your cat's health history
Frequently Asked Questions
How often should my cat have a CBC?
Healthy adult cats should have annual CBCs as part of wellness examinations. Senior cats (7+ years) may benefit from CBCs every 6 months, while cats with chronic conditions may need more frequent monitoring.
Does my cat need to fast before a CBC?
No, fasting is not required for a CBC. However, if your vet is also running a chemistry panel or other tests, fasting may be recommended. Always follow your veterinarian's pre-test instructions.
Can stress affect my cat's CBC results?
Yes, stress can cause temporary increases in white blood cell counts, particularly neutrophils. This is why your vet considers your cat's behavior and stress level when interpreting results.
What does it mean if my cat has regenerative vs. non-regenerative anemia?
Regenerative anemia means the bone marrow is responding by making new red blood cells (usually due to blood loss or destruction). Non-regenerative anemia suggests the bone marrow isn't responding properly, often indicating chronic disease or bone marrow problems.