Blog · Technology & Care

How to Read Dog & Cat Blood Tests: A Beginner's Guide

Published: May 24, 2026

Published by MaunaPet. Editorial policy and sources.

Editorial revision: October 1, 2026.

Leaving the veterinary clinic with a printed copy of your pet’s blood results can be intimidating. With countless abbreviations, cryptic numbers, and high/low reference ranges, it's easy to worry when a metric is slightly out of bounds. While only a veterinarian can properly diagnose your pet, understanding the basics of standard blood panels can give you great peace of mind. Let’s demystify the core components of veterinary blood work.

1. Complete Blood Count (CBC)

The **CBC** examines the cellular components of the blood, giving vital clues about your pet’s immune system, hydration levels, and oxygen-carrying capacity:

• Red Blood Cells (RBC): Cells that transport oxygen throughout the body. Low RBC count indicates anemia, while a high count often points to severe dehydration.
• White Blood Cells (WBC): The body’s primary defense system. Elevated levels indicate infection, inflammation, or extreme stress, while low levels can point to bone marrow conditions or viral attacks.
• Platelets (PLT): Crucial for blood clotting. Low levels (thrombocytopenia) can cause spontaneous bleeding or bruising.

2. Kidney Function Metrics

Kidneys filter waste products out of the blood. In both senior dogs and cats, kidney panels are vital for catching early renal insufficiency:

• BUN (Blood Urea Nitrogen): A waste product from protein breakdown. High levels can indicate kidney dysfunction, dehydration, or a high-protein diet.
• Creatinine (CREA): A waste byproduct of muscle breakdown. It is the most reliable indicator of kidney function. Elevates only when 75% of kidney capacity is compromised, making early monitoring critical.

3. Liver Function Metrics

The liver processes nutrients and filters toxins. Vets monitor these core liver enzymes:

• ALT (Alanine Aminotransferase): An enzyme that leaks into the blood when liver cells are damaged or inflamed.
• ALKP / ALP (Alkaline Phosphatase): Commonly elevated in senior pets. Can indicate bile duct obstruction, liver disease, or endocrine disorders like Cushing's disease.

4. Pancreas and Hydration Markers

• Amylase & Lipase: Enzymes produced by the pancreas. Significant elevations suggest pancreatitis, an incredibly painful inflammation.
• Total Protein (TP): Measures albumin and globulin in the blood. Highly useful for assessing hydration, liver function, and systemic inflammation. (You can check your dog's daily fluid balance with our Dog Water & Hydration Calculator).

A single high or low value does not automatically mean your pet is sick. Reference ranges are averages, and slight fluctuations are normal. Keep a digital repository of all past veterinary lab reports in MaunaPet, so you can easily compare metrics over time and spot shifts before they turn into symptoms.

Frequently Asked Questions

What do the main sections of a pet blood test mean?

A standard panel covers the Complete Blood Count (red cells, white cells, platelets), kidney markers (BUN, creatinine, SDMA), liver enzymes (ALT, ALP), and pancreas/hydration markers — together giving a broad picture of organ health.

What does a high BUN or creatinine mean in dogs and cats?

Elevated BUN and creatinine often point to reduced kidney function or dehydration. The newer SDMA marker can flag kidney disease earlier. Your vet interprets these together, not in isolation.

Should I interpret my pet's blood results myself?

Use the values to ask better questions, but leave diagnosis to your vet. Many results are affected by age, breed, dehydration, medication and the lab's reference ranges.

How often should pets have blood work done?

Healthy adults often get baseline blood work at annual exams; senior pets (7+) and those on long-term medication usually need it every 6 months to monitor organ function.