How to Read Cat Blood Test Results — Complete Guide

Understanding your cat's blood test results can feel overwhelming, but knowing the basics helps you ask better questions and make informed decisions about your feline's health.

Types of Cat Blood Tests

Most blood panels for cats include several key components:

Complete Blood Count (CBC) — Counts and examines blood cells including red blood cells, white blood cells, and platelets. For detailed CBC interpretation, see our complete guide to cat CBC results.

Chemistry Panel — Measures organ function, blood sugar, proteins, and electrolytes. Essential for detecting liver and kidney disease.

Thyroid Testing (T4) — Screens for hyperthyroidism, extremely common in senior cats over 10 years old.

Quick Reference: Normal Cat Blood Values

*Normal ranges may vary slightly between laboratories. Always consult your veterinarian for interpretation specific to your cat.

Understanding CBC Results

Red Blood Cell Values

RBC (Red Blood Cell Count): Normal range 5.0-10.0 million/μL. Low values suggest anemia; high values may indicate dehydration.

Hemoglobin (HGB): Normal range 8-15 g/dL. Carries oxygen throughout the body. Low levels indicate anemia.

Hematocrit (HCT): Normal range 24-45%. Shows percentage of blood made up of red blood cells. Low values mean anemia; high values suggest dehydration.

For detailed understanding of these values, see our comprehensive cat CBC explained guide.

White Blood Cell Values

WBC (White Blood Cell Count): Normal range 5,500-19,500/μL. High values often indicate infection or inflammation; low values may suggest immune system issues.

Neutrophils, Lymphocytes, Eosinophils: Different types of white blood cells that help identify specific conditions like bacterial infections, allergies, or stress.

Understanding Chemistry Panel Results

Liver Function Tests

ALT (Alanine Aminotransferase): Normal range 12-130 U/L. Elevated levels indicate liver cell damage or stress.

ALP (Alkaline Phosphatase): Normal range 14-111 U/L. Elevated levels can indicate liver disease or bile duct problems.

Understanding liver enzyme patterns is crucial for cat health. For detailed interpretation, see our complete guide to cat liver enzymes.

Kidney Function Tests

BUN (Blood Urea Nitrogen): Normal range 14-36 mg/dL. High levels may indicate kidney disease, dehydration, or high-protein diet.

Creatinine: Normal range 0.8-2.4 mg/dL. More specific for kidney function than BUN. Elevated levels suggest kidney problems.

SDMA: A newer, more sensitive marker for early kidney disease detection. For comprehensive kidney health information, see our cat kidney values explained guide.

Thyroid Function

T4 (Total Thyroxine): Normal range 0.8-4.7 μg/dL. High levels indicate hyperthyroidism, extremely common in senior cats.

Hyperthyroidism affects up to 10% of cats over 10 years old. If diagnosed, treatment often involves methimazole medication.

Other Important Values

Glucose: Normal range 74-159 mg/dL. High levels may indicate diabetes; low levels can be dangerous and need immediate attention.

Total Protein: Normal range 5.4-7.8 g/dL. Indicates nutrition status, liver function, and hydration.

Electrolytes (Sodium, Potassium, Chloride): Important for cellular function. Imbalances can indicate various health issues.

Age-Related Considerations

Senior Cats (7+ Years)

Older cats are more prone to:

• Hyperthyroidism (elevated T4)

• Chronic kidney disease (elevated BUN, creatinine, SDMA)

• Liver disease (elevated ALT, ALP)

• Diabetes (elevated glucose)

Senior cats benefit from twice-yearly bloodwork to catch these conditions early when treatment is most effective.

What Abnormal Results Mean

Slightly Abnormal Values

Values slightly outside normal ranges aren't always concerning, especially if your cat seems healthy. Factors that can affect results include:

• Stress from the vet visit

• Recent meals or fasting

• Medications

• Age-related changes

• Laboratory variation

Significantly Abnormal Values

Values well outside normal ranges typically require follow-up testing or treatment. Your vet will consider:

• How far outside normal the value is

• Your cat's clinical signs and symptoms

• Trends in previous bloodwork

• Other lab values and their patterns

When to Repeat Blood Tests

Your veterinarian may recommend repeat testing for:

• Borderline abnormal results to see if they normalize

• Monitoring chronic conditions like kidney or liver disease

• Checking response to treatment

• Pre-anesthetic screening before surgery

• Annual wellness monitoring, especially in senior cats

Questions to Ask Your Vet

When reviewing your cat's blood test results, consider asking:

• Which values are most important for my cat's age and health status?

• How do these results compare to my cat's previous bloodwork?

• Are any abnormal values related to medications my cat takes?

• What symptoms should I watch for at home?

• When should we recheck these values?

• Are there any dietary or lifestyle changes that might help?

Related Reading

• Cat CBC (Complete Blood Count) Explained – detailed guide to understanding CBC components

• Cat Liver Enzymes Explained – comprehensive guide to ALT, ALP, AST, and GGT

• Cat Kidney Values Explained – understanding BUN, creatinine, and SDMA

• Chronic Kidney Disease in Cats – stages, symptoms, and management

• Methimazole for Cats – treating hyperthyroidism detected through blood tests

Frequently Asked Questions