What Does a Blood Test Tell You About Your Dog or Cat? A Vet’s Guide to Common Results
A blood test tells your veterinarian how your pet’s organs, blood cells, and immune system are functioning right now. Most bloodwork visits run two panels together – a complete blood count (CBC) and a blood chemistry panel – and between them, these tests can flag infection, dehydration, organ stress, and other issues, often before your dog or cat shows any outward signs.
At Mascot Animal Hospital, our veterinary team runs these panels routinely as part of wellness exams, pre-anesthetic screening, and sick-pet visits. Below, we walk through what each test measures, what the results can mean, and when your vet might recommend a closer look.
Table of Contents
- Why Vets Recommend Routine Blood Work
- The Two Main Blood Tests Explained
- Complete Blood Count (CBC): What It Measures
- Blood Chemistry Panel: What It Measures
- What High or Low Values Can Indicate
- When Your Vet May Recommend Additional Testing
- Blood Testing at Mascot, Your Animal Hospital in Surrey
- Frequently Asked Questions
- The Bottom Line
Why Vets Recommend Routine Blood Work
Blood tests aren’t only for sick pets. Vets use them for several reasons:
- Baseline health data – so your vet knows what’s normal for your pet specifically.
- Early detection – many organ issues develop quietly, with no visible symptoms at first.
- Pre-anesthetic safety – bloodwork before surgery or dental cleanings checks that organs can safely process anesthesia.
- Monitoring chronic conditions – tracking values over time for pets on long-term medication or managing diabetes, kidney disease, etc.
- Investigating symptoms – vomiting, lethargy, weight loss, or increased thirst often start with bloodwork.
The Two Main Blood Tests Explained
Most bloodwork panels combine two separate tests, drawn from the same blood sample but measuring different things.
Complete Blood Count (CBC): What It Measures
A CBC counts and examines the cells that make up your pet’s blood.
| Component | What It Measures | Possible Meaning if Abnormal |
|---|---|---|
| Red blood cells (RBC) | Oxygen-carrying capacity | Low = anemia; high = dehydration or other causes |
| White blood cells (WBC) | Immune response | High = infection or inflammation; low = certain infections or bone marrow issues |
| Platelets | Blood clotting ability | Low = bleeding risk; may need further testing |
| Hemoglobin / hematocrit | Blood’s oxygen-carrying protein and volume | Low values often point to anemia or blood loss |
Blood Chemistry Panel: What It Measures
While a CBC looks at cells, a chemistry panel measures substances dissolved in the blood – mainly enzymes, proteins, and electrolytes that reflect how organs are functioning.
| Category | What It Measures | Possible Meaning if Abnormal |
|---|---|---|
| Liver enzymes (ALT, ALP) | Liver and bile duct function | Elevated values can point to liver stress or disease |
| Kidney values (BUN, creatinine) | Kidney filtering function | Elevated values may suggest reduced kidney function |
| Electrolytes (sodium, potassium, chloride) | Hydration and nerve/muscle function | Imbalances can relate to dehydration, vomiting, or organ disease |
| Glucose | Blood sugar | High = possible diabetes; low = specific causes |
| Total protein / albumin | Hydration, liver, and kidney status | Low levels can suggest liver, kidney, or nutritional issues |
What High or Low Values Can Indicate
A single out-of-range number is a starting point, not a diagnosis. Vets look at the whole panel together, plus your pet’s history and exam findings, before drawing conclusions. A few general patterns:
- One mildly elevated value with everything else normal often needs a recheck rather than immediate treatment.
- Several related values moving together (e.g., both liver enzymes) carry more weight than one number alone.
- Trends over time – comparing this year’s bloodwork to last year’s – can be more useful than a single snapshot.
When Your Vet May Recommend Additional Testing
Bloodwork sometimes points toward, rather than confirms, a diagnosis. Your vet may suggest follow-up testing when:
- CBC or chemistry values fall outside the normal range.
- Your pet is a senior and due for periodic screening.
- Bloodwork is needed to clear your pet for anesthesia or surgery.
- A chronic condition – like kidney disease or diabetes – needs ongoing monitoring.
- Breed or age puts your pet at higher risk for a specific condition.
Follow-up options can include urinalysis, imaging (X-ray or ultrasound), or a repeat blood draw a few weeks later to check for trends.
Blood Testing at Mascot Animal Hospital
Mascot Animal Hospital is a full-service animal hospital in Surrey, offering in-house and reference lab bloodwork for cats and dogs. Most in-house results are ready the same day, and our veterinarians go through each value with you in plain language rather than handing over a printout and moving on.
Whether your pet is due for a wellness panel, needs pre-surgical clearance, or is showing symptoms that warrant a closer look, our team can run and explain the right tests for their age, breed, and health history.
Learn more about our diagnostic services and the testing options available at Mascot Animal Hospital
For pet owners who want a deeper reference on how veterinarians interpret bloodwork, the American Animal Hospital Association’s guide to dog blood work is a solid, vet-reviewed resource.
Frequently Asked Questions
How often should my dog or cat have blood work done?
Most healthy adult pets benefit from annual bloodwork as part of a wellness exam. Senior pets, or those with ongoing health conditions, are often tested every six months.
Does my pet need to fast before a blood test?
For some tests, yes — fasting can affect glucose and lipid values. Your vet will let you know if fasting is needed before your pet’s appointment.
Can a blood test diagnose cancer in dogs or cats?
Bloodwork alone usually can’t confirm cancer, but abnormal results can prompt further testing — such as imaging or biopsy — that leads to a diagnosis.
What does it mean if one value on the panel is slightly out of range?
It often means very little on its own, especially if the rest of the panel looks normal. Your vet may simply recheck it at the next visit to confirm it isn’t a trend.
The Bottom Line
A blood test gives your vet a window into your dog or cat’s health that a physical exam alone can’t provide — catching changes in organ function, hydration, and immune response early, when they’re easiest to manage.
Due for a wellness exam or bloodwork?
Contact Mascot to book an appointment, and our team will walk you through your pet’s results in person.
