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Blood Tests for Dogs: Everything You Need to Know

At A Glance

Blood tests are an essential tool to determine the health status of your pet. Canine blood work is required before anesthetic use, to monitor existing drug therapies, and diagnose severe illness.

Learn how to understand blood tests and to prepare your dog for sample collection.

Last Updated on: Apr 04, 2022

Canine blood work helps monitor and examine a dog’s health on a cellular level. Blood tests for dogs test for issues beyond what meets the eye and they help pinpoint problematic areas. These tests also provide a thorough understanding of what’s wrong with your dog and how it can be fixed. Lets understand everything there is to know about dog blood tests.

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vials of blood

When Does a Pet Need a Blood Test?

Your pet could be ill due to various issues and your vet’s job is to look for the root cause of imbalance, discomfort, or disease. If your vet has advised you to take your dog for a blood test, it’s because a physical examination isn’t enough.

Blood tests examine your dog’s blood cell type and give you an overall understanding of how the organs are functioning. Typically, your dog needs a blood test every time a vet asks for one. A Complete Blood Count (CBC) and blood-chemistry evaluation make it easier to diagnose any condition and suggest effective treatment.

Here are a few important reasons why your pet needs a blood test.

When Your Pet is Sick

When dogs feel unwell, they display symptoms like fatigue, sleepiness, and a loss of appetite. Under normal circumstances, your dog’s body will bounce back after a short period of rest. If this doesn’t happen and your dog’s symptoms get worse, your vet may ask you to take a blood test.

“Countless times I have been so surprised by the results I’ve found on bloods and so grateful that I was able to run them before making any treatment decisions. They really can change the outcome for your pet.” says Dr. Kim, a general practitioner in Brisbane, Australia.

Several different conditions invariably cause symptoms. A basic blood test is the first step towards a sound diagnosis and it’s only after a blood test analysis that the vet can effectively suggest the best course of treatment for your pet.

an image of a dog at the clinic

To Check for Drug Levels

When your dog is on routine medication, your vet may want to check the drug levels in its blood which impact organs like the liver and kidneys. If your pet is on long-term medication, the drug levels can affect its bone marrow too.

Even if your dog isn’t exhibiting any signs of any visible discomfort, your vet may suggest taking a blood test as a preventive measure or to detect abnormalities.

dog getting his treatment

Before a Surgery

A wide range of surgeries, even minor ones, require anesthetics. Usually, the waste material from anesthetic medications leaves the body through the kidneys and liver. The only way to know if your dog’s organs are functioning optimally is to take a blood test. Based on the results, your vet may have to consider an alternative course of treatment if there are discrepancies.

After a surgical procedure, you must make sure your dog recovers completely and also check whether its body reacts normally to the anesthesia. A blood test rules out the possibility of further complications.

Before A Treatment Plan

Dogs above the age of seven often react adversely to medication. This may also be because of some pre-existing condition or disease. You must ensure that you don’t hinder the chemical balance in your dog’s blood and organs with intrusive medication. Therefore, performing a blood test will tell you whether its organs are in good shape before putting it on additional medication.

When Your Dog Gets Older

As your pet crosses a certain age, it is more susceptible to contract severe illnesses like kidney malfunction, Cushing disease, thyroid problems, or anemia. Older dogs also develop dental problems and arthritis as they age. A bi-annual blood test can help in detecting and diagnosing these conditions at the early stages.

With the blood work results, your vet will be able to understand what’s wrong with your pet and spare it a lot of pain and trouble. Performing a blood test detects whether your dog is distressed because of any of these problems.

To Fight The Impact of Toxins

It’s not unusual for your pet to accidentally consume harmful toxins from household items like onions, apple seeds, or chocolate. These toxins when consumed are known to cause blood clotting, liver or kidney impairment, or anemia.

In such cases, your dog needs immediate medical attention and a blood test is the first step towards damage control. Vets also recommend that you check your dog’s ‘baseline’ blood after the treatment to see how the medication is working.

dog at the hospital for a checkup

Understanding Your Dog’s Blood Test

“The value of blood tests is inestimable, but the veterinarian’s physical exam, history, and other observations will always be indispensable.” says Dr. Joe Zinkel, Veterinarian at the Davis School of Veterinary Medicine.

Canine blood work is an extensive analysis of your dog’s complete blood count, blood serum proteins, hormones, and electrolytes.

Complete Blood Count

A CBC test will reveal your dog’s hydration levels, underlying infections, susceptibility to blood clotting, and optimum immune system response.

When a dog shows signs of fever, diarrhea, fatigue, a loss of appetite, pale gums, and vomiting, a CBC is mandatory to confirm the cause of the issue. Just before surgery, vets ask for a CBC test to rule out the occurrence of bleeding issues and the presence of abnormalities.

Here’s what a CBC can tell you.


A primary component of a CBC, hematocrit, refers to the scale of red blood cells in your pet’s blood. Blood generally comprises white blood cells (WBCs), red blood cells (RBCs), and platelets. Low hematocrit levels are a sign of anemia, while high levels reaching up to 45% signal dehydration.


Hemoglobin is the portion of red blood cells that contains iron and carries oxygen. A low or high count of hemoglobin may make your veterinarian evaluate other measurements to ascertain the problem.

White Blood Cell Count

White blood cells, dispersed in the plasma, form the foundation of your dog’s immune system. WBCs are immune cells that fight diseases. However, if your pet’s white blood cell count falls or rises, it usually confirms an infection.

Granulocytes and Lymphocytes/Monocytes

Your dog’s blood contains granulocytes and lymphocytes/ monocytes. They are characterized as little granules in white blood cells. These particles are the first to react to sudden trauma and inflammation in the body. A low GRAN count can lead to acute and chronic infections.


To check for allergies you need to test for an accurate measure of eosinophils. These are a variety of white blood cells. Elevated levels of eosinophils indicate allergies, skin disorders, or parasitism.

Platelet Count

Platelets make sure blood clots normally. They are also referred to as thrombocytes and they stem from the bone marrow. If your dog has bled profusely or has pre-existing blood clotting problems, the platelet count in your dog’s blood reduces and this could also cause a hemorrhage. An increased platelet count, however, doesn’t lead to any substantial consequences.


Reticulocytes are a younger version of red blood cells. They are still developing which is why they are also called immature red blood cells. If RETICs are detected in higher amounts, your dog could have anemia. This condition is called, “reticulocytosis.”


Fibrinogen is a fibre-filled glycoprotein that propels platelets to gather and create blood clots. A high level of fibrinogen usually means your dog is healthy, however, decreased levels can indicate liver malfunctions or internal bleeding. In female dogs, fibrinogen levels increase when they are 4-5 weeks pregnant and also after an abortion.

an image of a sick dog

Blood Serum Test

A blood serum test is a part of dog blood tests that reveal your dog’s electrolyte status, hydration levels, organ function, and hormone profile and it’s crucial to its overall health. Getting a blood serum test done before any planned procedure or surgery will eliminate the occurrence of side effects and will ensure that the surgery is successful in the long term.

The following blood tests should be done particularly for older dogs who are more vulnerable to health problems:


A serum protein called albumin is an element in your dog’s blood that retains fluid in the bloodstream and prevents it from seeping into its urine. Albumin helps monitor kidney and liver functions. Low levels of albumin are a sign of hydration issues and liver and kidney diseases.

Alkaline Phosphatase

An ALP test determines the levels of alkaline phosphatase enzymes in your dog’s blood. When this enzyme’s levels increase or decrease, it usually hints at conditions like gallstones or sometimes even cancer.

Alanine Aminotransferase

Checking for an accurate count of alanine aminotransferase can predict liver damage. This liver enzyme helps convert your dog’s food into energy. It is found in tiny amounts in the blood and they multiply when your dog’s liver cells are compromised because of an injury or an infection.


If the blood test indicates an elevation in the levels of amylase in the blood, your vet may want to treat your dog for pancreatitis or kidney infections.

Aspartate Aminotransferase

To confirm whether your dog has liver disease, your vet will check for increased levels of aspartate aminotransferase. Increased levels of this enzyme can even indicate skeletal or muscle damage.

Blood Urea Nitrogen

The blood urea nitrogen count in the blood helps evaluate your dog’s kidney function. If its levels increase, it’s probably because of kidney impairment, heart disease, or shock.


Imbalances in calcium levels indicate that your dog may have a tumor or a kidney disorder.

Cushing’s disease can affect older dogs when cholesterol levels increase in their blood. Checking for cholesterol levels in your dog’s blood can help diagnose Cushing’s disease and also hyperadrenocorticism.


If there’s a dip in chloride content in your dog’s blood, it could lead to symptoms like excessive vomiting. In such a case, a blood test will help check for dehydration or other diseases.

To find out whether your dog has Addison’s disease, it’s crucial to check the extent of cortisol present in the blood.

an image of a sick dog


Creatinine is a urine protein. It supports your dog’s metabolism. If it increases in concentration, this test could show signs of possible kidney malfunction.

Serum Protein Test

A serum protein test is a measure of the scale of protein in your dog’s blood. When serum protein levels are elevated, your dog may be combatting liver disease, lupus, and other severe infections.

Lactate Dehydrogenase

Lactate Dehydrogenase (LDH) is an enzyme that breaks sugar down to energy. If its levels increase, it could damage the cells in the blood, muscles, liver, and heart.


Potassium aids in nerve function, muscle contraction and stabilizes your dog’s heart rate. This electrolyte transports nutrients into cells and expels nutrient waste out of them. High potassium levels in dogs indicate possible kidney failure. Potassium levels also dip when your dog suffers from dehydration, diarrhea, or continuous urination.


Dogs need to maintain normal levels of a hormone called thyroxine in their blood. This hormone supports muscle health, bone development, and digestion. On the other hand, low levels of thyroxine indicate hypothyroidism.

an image of a dog with the doctor


Glucose levels are the primary measure of blood sugar in dogs. If they increase, your dog may have diabetes or obesity. If your dog has a seizure or goes into a coma, it’s probably because of a decrease in blood sugar or glucose levels in the blood.


Bilirubin is a vital component of your dog’s digestive system. It is transmitted into the bloodstream by the liver and can be found in the gallbladder. When its levels increase, it can indicate the presence of liver disease.


Phosphorus is a mineral that supports your dog’s bones and teeth and helps them form. If your dog’s blood reports indicate a high concentration of phosphorus, it may be suffering from bleeding disorders. On the other hand, low levels are an indication of thyroid issues.

dog at the hospital

Why Are Canine Blood Tests Important?

“My clinical experience demonstrates the most common diseases as renal disease, then diabetes, and third, either hypothyroidism or Cushing’s disease. Fortunately, if a client will avail himself of them, there are many clues blood tests can give us when these diseases are in progress, especially for geriatric animals.” says Dr. Fred Metzger, a Veterinarian from Pennsylvania.

Many factors determine a dog’s health and a detailed blood test can help detect any problems.

Understanding a dog’s blood tests may seem complex at first but the results will help your vet diagnose diseases and find solutions.

Physical Examination Isn’t Enough

Sometimes, dogs don’t display any symptoms of apparent diseases but there might be some changes in their behavior. Little differences in regular behavior like the sudden refusal to go for walks, limping after getting up, experiencing pain while cleaning out bowels, excessive urination, or a lack of energy and appetite is enough reason to get your dog’s blood tested.

A physical examination alone will only reveal your dog’s physical condition but it won’t reveal issues that are inside its body.

Canine blood work is necessary to discover underlying problems that you would otherwise be unable to detect. It will also help your vet treat the source of the problem and not just manage the symptoms.

If your dog is at risk of contracting any disease, it’s better to know about it at the earliest for a long-term solution.

Blood tests for dogs

Testing for Evidence and Clarity

Dog blood tests scrutinize your dog’s blood for:

  • Proteins
  • Electrolytes
  • Glucose
  • Endocrine hormones

More importantly, blood serum tests can uncover the intricate workings of your dog’s endocrine system. Given the fact that the endocrine system assists your dog in responding aptly to his environment and internal triggers, a blood chemical test that checks for endocrine hormone levels that are secreted in the blood is a must for dogs of all ages.

Endocrine disorders in dogs often result in a thyroid imbalance. Diseases that could arise are Cushing’s disease and Addison’s disease. Testing your dog’s blood can bring these issues to light. It’s best to get it tested to detect common, age-related health disorders early on. This way, your vet has enough time to come up with a treatment plan that won’t damage your dog’s system.

Means to An Early Diagnosis

Blood tests are as crucial for a 10-month-old puppy that’s ready to be neutered as they are for older dogs who seem ill. It’s highly likely that at least one out every 10 dogs has defected or abnormal blood values but seem perfectly healthy and completely devoid of any visible health conditions.

Blood tests aren’t always conducted during an emergency. They are also a vital diagnostic mechanism to prevent future issues. Common diseases like diabetes, hypothyroidism, hyponatremia, and more can be tackled earlier on by checking your dog’s blood for glucose levels, sodium content, and hormone secretions.

Blood tests are also critical before any planned procedures and drug therapies.

Vets recommend blood tests to test for potential threats, possible obstructions during surgery and recovery, and an early diagnosis of underlying diseases.

Once tested, the next step is to devise a sound treatment plan that caters to your dog’s physiological needs.


How to Prepare Your Dog for a Blood Test?

“By having your pet properly prepared for each visit you may save valuable time and money.” say experts at VCA Hospitals. Here are ways in which you could get your dog ready for a blood test.

An image of dog eating

Limit Food Intake

You must make sure you don’t feed your dog for six hours before a blood test to avoid fat from forming in the blood. Vets recommend fasting before taking a blood test as it drains lipemia from the blood. Lipemia, when present in a blood sample, is known to hamper the test results.

An image of dog drinking water

Encourage Hydration

A dehydrated dog may force inaccurate blood test results. The results will be inconclusive and you may have to repeat the test for more accuracy. So you should make sure your dog has enough water before a blood test.

Minimize Physical Activity

You must ensure that your dog is calm and relaxed before a blood test. Some dogs also tend to get anxious and excited when they visit the vet’s clinic. Excessive chewing, eating, and active play can alter your dog’s blood tests reports.

It’s ideal to schedule the sample collection at a time when the clinic is less crowded to avoid coming in contact with a lot of strangers and other dogs.

Special tests require a longer period of fasting which could be up to 12 hours. In some cases, your vet may prescribe certain pre-test medications. Make sure you give your dog the right dosage of these pre-test medications at the right time.

If the vet recommends that you refrain from giving your dog medication hours before the sample is collected, be sure to do so.

Check out this article on how to give your dog medicine.

An image of a dog looking at the owner

Frequently Asked Questions

Here are the answers to some of the most frequently asked questions about blood tests for dogs.

How Often Should a Blood Test Be Done?

Usually, your puppy will need a blood test before a routine surgery like spaying or neutering. Otherwise, it’s best to get your dog’s blood tested annually once it turns 5 years old. Once your dog becomes a senior, which is above the age of 10, you might want to sign up for blood and urine tests bi-annually.

How is Blood Drawn from My Dog?

For routine blood tests, a blood sample is drawn from the jugular vein in your dog’s neck. Once drawn, it’s collected and stored in a lab tube with a colored lid and a tag indicating the name of the test and your dog’s ID number. Typically, it takes about 10 seconds to draw the blood from your dog.

How Long Does it Take to Get Results from a Blood Test?

Depending on the nature of the test, blood panel test results could take up to 24 hours. Sometimes it could take a few days or even two weeks. It’s best to check with the lab once you’ve given them your dog’s blood sample.

How Much Does a Blood Panel Cost for Dogs?

A blood panel test for dogs including a routine urine analysis test ranges between $90 – $250. 

Do Blood Tests Hurt Dogs?

When collecting a blood sample, your dog might feel a slight prick caused by the needle used to draw the blood. The pain levels are minimal and overall, blood tests don’t hurt dogs.



Meet Paul, a devoted dog dad to the delightful French Bulldog, Cofi. With a flair for humor and a deep understanding of Frenchie quirks, Paul brings a lighthearted touch to his writings. His relatable stories and practical insights are a blend of laughter and valuable advice and resonate with fellow dog owners.

Through his words, Paul aims to celebrate the joys and challenges of being a dedicated pet parent, reminding you that life is simply better with a four-legged, snorting sidekick by your side.