The Importance of Laboratory Results#
Veterinary technicians play a critical role in the proper interpretation of laboratory results. Incorrect or delayed interpretation can lead to wrong diagnosis and treatment. This guide provides a practical resource for interpreting the most common laboratory tests.
Critical Note
Critical values must be reported to the veterinarian immediately! Some laboratory results require urgent intervention and delays can be life-threatening.
Complete Blood Count (CBC)#
CBC measures the number and ratios of cells in the blood. It reveals many conditions including infection, anemia, and coagulation problems.
| Parameter | Reference (Dog) | Reference (Cat) | High Means | Low Means |
|---|---|---|---|---|
| WBC (Leukocyte) | 6-17 x10³/μL | 5.5-19.5 x10³/μL | Infection, stress, inflammation | Immune deficiency, bone marrow issue |
| RBC (Erythrocyte) | 5.5-8.5 x10⁶/μL | 5-10 x10⁶/μL | Dehydration, polycythemia | Anemia, bleeding |
| HGB (Hemoglobin) | 12-18 g/dL | 9-15 g/dL | Polycythemia | Anemia |
| HCT (Hematocrit) | 37-55% | 30-45% | Dehydration | Anemia, bleeding |
| PLT (Platelet) | 200-500 x10³/μL | 300-800 x10³/μL | Thrombocytosis | Bleeding risk |
CBC Reference Values and Interpretations
Leukocyte Differential#
The leukocyte differential shows the percentages of different white blood cell types:
- Neutrophil ↑: Bacterial infection, stress, inflammation
- Lymphocyte ↑: Viral infection, chronic infection
- Monocyte ↑: Chronic inflammation, tissue damage
- Eosinophil ↑: Parasites, allergies
- Basophil ↑: Rare, hypersensitivity
Practical Tip
"Left Shift": Increase in immature (band) neutrophils indicates acute infection. Must be reported to the veterinarian.
Biochemistry Panel#
Biochemistry evaluates organ function. It provides information about the health status of organs like the liver, kidneys, and pancreas.
| Parameter | Reference | High | Low |
|---|---|---|---|
| ALT | 10-100 U/L | Liver damage | Rare, not significant |
| ALP | 20-150 U/L | Liver, biliary tract, Cushing's | Rare |
| BUN | 7-27 mg/dL | Kidney failure, dehydration | Liver damage |
| Creatinine | 0.5-1.8 mg/dL | Kidney failure | Muscle loss |
| Glucose | 70-143 mg/dL | Diabetes, stress, Cushing's | Hypoglycemia, insulinoma |
| Total Protein | 5.2-8.2 g/dL | Dehydration, myeloma | Malnutrition, loss |
Biochemistry Reference Values
Liver Enzymes#
ALT (Alanine Aminotransferase)
Liver-specific enzyme. Elevation indicates hepatocyte damage. Causes may include toxicity, infection, hepatitis.
Critical Value: Elevation more than 3 times the upper normal limit requires urgent intervention.
AST (Aspartate Aminotransferase)
Elevated in liver and muscle damage. Should be evaluated together with ALT. AST high + ALT normal = muscle damage suspicion.
ALP (Alkaline Phosphatase)
Biliary tract, bone metabolism. Naturally higher in young animals (bone development). In adult animals, elevation raises suspicion of biliary obstruction, Cushing's disease.
