Vet Guide to Lab Values for Dogs and Cats: What Bloodwork Really Tells You
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Vet Guide to Lab Values for Dogs and Cats: What Bloodwork Really Tells You 📊🐶🐱
By Dr Duncan Houston
Blood tests are one of the most powerful diagnostic tools veterinarians use. They allow us to look inside your pet’s body and understand what is happening beneath the surface.
As an emergency veterinarian, bloodwork is something I rely on almost every shift. Sometimes it confirms a diagnosis quickly. Other times it helps rule out serious disease and reassures worried owners that their pet is doing well.
For pet owners, though, lab reports can look confusing. Pages of numbers, abbreviations, and bold values can feel intimidating.
This guide explains the most common blood and urine tests used in dogs and cats and what they actually tell veterinarians about your pet’s health.
📑 There Is No Single “Normal” Value
One of the most important things to understand is that normal lab ranges are not identical for every pet.
Values can vary depending on:
🐾 Species such as dog versus cat
🐶 Breed differences such as Greyhounds or sighthounds
🎂 Age including puppies, kittens, and seniors
💊 Medications or supplements
🍖 Whether your pet recently ate
😰 Stress during the veterinary visit
Because of this, a single abnormal number does not automatically mean something is wrong. Veterinarians interpret results together with the physical exam, medical history, and symptoms.
Bloodwork tells a story. The numbers only make sense when we read the whole story.
🩸 Complete Blood Count (CBC)
The Complete Blood Count evaluates the cells circulating in the bloodstream.
It helps veterinarians detect infections, inflammation, anemia, immune disease, and clotting disorders.
❤️ Red Blood Cells (RBC)
Red blood cells carry oxygen throughout the body.
Low RBC levels may indicate anemia, which can occur due to:
• blood loss
• immune disease
• parasites
• chronic illness
• bone marrow disease
High RBC levels may occur with dehydration or certain rare disorders.
🧬 Hematocrit (PCV)
Hematocrit, also called Packed Cell Volume (PCV), measures the percentage of blood made up of red blood cells.
Low hematocrit suggests anemia.
High hematocrit often indicates dehydration.
Emergency veterinarians frequently use PCV to quickly assess sick patients.
🔬 White Blood Cells (WBC)
White blood cells are part of the immune system and help fight infection and inflammation.
High WBC counts may indicate:
• bacterial infection
• inflammation
• immune disease
• stress responses
Low WBC counts may occur with severe infection, bone marrow disease, or certain viral illnesses.
🧫 Differential White Blood Cell Count
Veterinarians also evaluate different types of white blood cells, which provide important diagnostic clues.
Neutrophils
Often increase with bacterial infection or inflammation.
Lymphocytes
Associated with immune responses and certain cancers.
Monocytes
Often increase with chronic inflammation.
Eosinophils
Commonly elevated with allergies or parasites.
Basophils
Rare but sometimes seen in allergic disease.
Patterns in these cells often reveal more information than the total WBC count alone.
🩸 Platelets
Platelets help blood clot after injury.
Low platelet counts increase the risk of bleeding and may occur with immune diseases, infections, toxins, or certain cancers.
🧪 Blood Chemistry Panel
A biochemistry panel evaluates organ function, metabolism, and electrolyte balance.
These tests help veterinarians assess the liver, kidneys, pancreas, muscles, and endocrine system.
🧬 ALT (Alanine Aminotransferase)
ALT is a liver enzyme released when liver cells are damaged.
High ALT may occur with:
• liver inflammation
• toxins
• infections
• medication effects
🧪 ALP (Alkaline Phosphatase)
ALP is another enzyme associated with the liver and bile ducts.
In dogs, ALP may increase with:
• steroid medications
• Cushing’s disease
• bone growth in young animals
In cats, elevated ALP more strongly suggests liver or bile duct disease.
⚠️ Liver Enzymes vs Liver Function
Many pet owners assume liver enzymes measure liver function.
In reality, ALT and ALP measure liver cell irritation or injury, not how well the liver works.
True liver function tests include:
• bile acids
• albumin
• bilirubin
• clotting factors
🍖 Amylase and Lipase
These digestive enzymes help break down carbohydrates and fats.
They may increase with pancreatitis, although diagnosis often requires additional testing.
🧪 Specific Pancreatitis Tests (PLi)
Veterinarians now commonly use PLi tests to diagnose pancreatitis more accurately.
These tests measure pancreatic lipase, an enzyme released specifically from the pancreas during inflammation.
Two common tests include:
cPLi (canine pancreatic lipase) for dogs
fPLi (feline pancreatic lipase) for cats
High PLi levels strongly suggest pancreatitis.
These tests are far more specific than older markers like amylase or lipase alone.
🧡 Bilirubin
Bilirubin forms when red blood cells break down.
High bilirubin may indicate:
• liver disease
• bile duct obstruction
• destruction of red blood cells
Very high levels can cause jaundice, leading to yellow gums, skin, or eyes.
💧 BUN (Blood Urea Nitrogen)
BUN measures a waste product filtered by the kidneys.
High BUN may occur with:
• kidney disease
• dehydration
• gastrointestinal bleeding
Low BUN may occur with severe liver disease.
💪 Creatinine
Creatinine is another waste product filtered by the kidneys.
High creatinine often indicates reduced kidney function or dehydration.
Muscle mass can also influence creatinine levels.
🧬 SDMA
SDMA is a newer kidney marker that can detect kidney disease earlier than creatinine.
It may identify kidney dysfunction before symptoms appear.
⚡ Electrolytes
Electrolytes regulate hydration, nerve signals, and muscle function.
Important electrolytes include:
Potassium
High potassium may occur with urinary obstruction or kidney failure.
Low potassium may occur with vomiting, diarrhea, or certain medications.
Sodium
Low sodium is commonly associated with Addison’s disease.
High sodium often reflects dehydration.
Chloride
Helps regulate fluid balance and acid base status.
Veterinarians often interpret electrolytes together when diagnosing metabolic disorders.
⚖️ Calcium
Calcium must remain tightly regulated in the body.
High calcium may occur with:
• certain cancers
• kidney disease
• hormonal disorders
Low calcium may occur with toxin exposure or metabolic disease.
🍭 Glucose
Glucose measures blood sugar.
High glucose may occur with diabetes, stress, or Cushing’s disease.
Cats commonly experience stress hyperglycemia, where glucose rises temporarily due to anxiety during a veterinary visit.
Low glucose may occur with severe infection, insulin producing tumors, or starvation.
❤️ ProBNP and Heart Disease
A test called NT-proBNP helps veterinarians assess heart disease in dogs and cats.
This marker measures a hormone released when the heart muscle is stretched or under stress.
Elevated NT-proBNP levels may indicate:
• heart failure
• cardiomyopathy in cats
• dilated cardiomyopathy in dogs
• fluid buildup in the chest caused by heart disease
This test is especially useful when pets show symptoms like:
• coughing
• breathing difficulty
• exercise intolerance
• fluid in the lungs
ProBNP testing can help veterinarians distinguish heart disease from lung disease when pets present with breathing problems.
🧪 Total Protein, Albumin, and Globulin
These proteins help evaluate liver function, immune activity, and hydration.
Low albumin may occur with liver disease, intestinal disease, or kidney protein loss.
High globulin levels may occur with infection, inflammation, or certain cancers.
💦 Urinalysis
A urinalysis provides additional information about kidney function and urinary health.
Urine testing helps detect:
🚽 urinary tract infections
💧 hydration status
🍭 glucose suggesting diabetes
🧬 protein indicating kidney disease
🔬 crystals or abnormal cells
Urine samples may be collected by free catch, catheter, or cystocentesis.
🩺 Common Reasons Veterinarians Run Blood Tests
Bloodwork is commonly recommended for:
• annual wellness exams
• senior pet health screening
• diagnosing illness
• monitoring chronic diseases
• evaluating medication safety
• pre anesthetic screening before surgery
💉 Pre Anesthetic Bloodwork
Before anesthesia, veterinarians often perform blood tests to evaluate organ function.
These tests help ensure a pet can safely metabolize anesthetic drugs.
Pre surgical testing commonly evaluates:
• liver function
• kidney function
• red blood cell levels
• electrolyte balance
This significantly improves anesthesia safety.
📈 Trends Matter More Than Single Numbers
Veterinarians often care more about changes over time than a single lab result.
For example:
A creatinine value that gradually rises each year may indicate early kidney disease even if the value is still within the reference range.
Tracking trends helps detect disease earlier and monitor treatment success.
🧪 In House Labs vs Reference Labs
Many veterinary clinics run blood tests using in house analyzers, which provide results within minutes.
These are extremely useful during emergencies.
Some tests are sent to reference laboratories, which perform more specialized diagnostics and detailed analysis.
Both types of testing play an important role in veterinary medicine.
📊 Monitoring Chronic Disease
Bloodwork is essential for managing chronic conditions such as:
• kidney disease
• diabetes
• liver disease
• thyroid disease
• autoimmune disorders
Regular testing allows veterinarians to adjust treatments and track disease progression.
🚨 When Lab Results Look Abnormal
Sometimes a value appears abnormal even when a pet seems healthy.
In these situations your veterinarian may:
🔁 repeat testing
🧪 run additional diagnostics
📊 monitor trends over time
🩺 interpret results alongside symptoms
A single abnormal value rarely tells the full story.
🎯 Final Thoughts
Lab values may look like confusing numbers, but they provide veterinarians with incredibly valuable insight into your pet’s internal health.
Blood tests allow early disease detection, guide treatment decisions, and help monitor how well therapies are working.
If your pet has blood tests performed, do not worry about interpreting every number yourself. Your veterinarian will explain the results in the context of your pet’s overall health.
❓ Frequently Asked Questions
Should healthy pets have blood tests?
Yes. Routine bloodwork during wellness exams can detect early disease before symptoms appear.
What if one lab value is slightly abnormal?
A single abnormal value does not always indicate disease. Veterinarians interpret results together with symptoms, history, and trends.
Do dogs and cats have the same lab ranges?
No. Species, breed, and age can significantly influence reference ranges.
How long does it take to get blood test results?
Many clinics can run tests in house and provide results within minutes. Some specialized tests may take longer if sent to reference laboratories.
If you ever want help understanding your pet’s test results, storing veterinary records, or tracking your pet’s health over time, the ASK A VET™ app can help pet owners stay organised and access veterinary guidance whenever they need it. 🐾
