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Veterinary Diagnostics: How Lab Work Can Keep Your Dog Healthy

Veterinary Diagnostics: How Lab Work Can Keep Your Dog Healthy

There are a number of reasons why your vet may recommend veterinary testing for your pup. It doesn't necessarily mean they are sick. Here, our St. Louis vets share some of the different types of pet laboratory diagnostic tests that they may ask for and what this lab work shows us about your dog.

Why Do Dogs Need Lab Work?

There are a bunch of different types of lab work, and usually, those are performed when we have to try to figure out what may be causing your dog to be ill. It doesn't have to be related to illness, but usually, lab work is done to discover the cause of an illness or to detect if there's any illness there at all, like in the case of heartworm disease or intestinal worms. It's not always obvious, but we do veterinary laboratory work to see if those things exist in that particular patient.

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What Are The Different Types of Lab Work?

While there are a number of individual tests that fall under the category, you may usually just hear the umbrella term lab work. But what are the different tests that fall under veterinary laboratory diagnostics?

Here are some of the most commonly requested types of lab work and how we use our St. Louis vet lab to provide the most accurate information possible:

Heartworm Tests

Heartworm disease is typically transmitted through the bite of an infected mosquito. These mosquitos carry a parasitic worm known as Dirofilaria immitis.

Pets such as cats, dogs, and ferrets can become the hosts of these parasites, this means that the worms live inside your dog, mature into adults, mate, and produce offspring. This serious condition is called heartworm disease because the worms live in the heart, lungs, and blood vessels of infected animals. 

Unfortunately, the signs of heartworm disease don't usually begin to appear in dogs until the disease becomes more advanced. The most common symptoms of heartworm disease include swollen abdomen, coughing, fatigue, weight loss, and difficulty breathing. 

Your vet is able to conduct blood tests using the veterinary laboratory to look for heartworm proteins (antigens), that are released into the dog's bloodstream. Heartworm proteins can't be detected until approximately five months (at the earliest) after a cat or dog has been bitten by an infected mosquito.

You need to know that treatment for heartworm disease could lead to serious complications and be potentially toxic to the body of your dog. Not only this, but the treatment is also expensive because it requires multiple visits to the vet, hospitalization, X-rays, bloodwork, and a series of injections. This is why our St. Louis vets say prevention is the absolute best way to treat heartworm disease. 

Although, if your cat or dog is diagnosed with heartworms, your vet will have treatment options available in their veterinary pharmacy. FDA-approved melarsomine dihydrochloride is a drug that contains arsenic and kills adult heartworms. To treat the disease melarsomine dihydrochloride will be administered via injection into your dog's back muscles.

Fecal Testing

Fecal exams are completed using the veterinary diagnostics lab at your primary care vet's office and are a microscopic examination of your dog's feces. These yearly exams help your vet find and treat any infections that might be compromising the health of your dog and even the health of everyone in your household.

When conducting a fecal exam your veterinarian will check for any signs of parasites such as hookworms and roundworms. These parasites could make your dog uncomfortable and irritable, as well as lead to many more serious conditions. A handful of parasites can even be transmitted to humans.

Intestinal parasites typically hide in the gastrointestinal tract of your dog. This makes fecal exams the most reliable way of diagnosing these parasites.

You should bring your dog to our St. Louis vet lab to be tested for internal parasites at least once a year. Puppies and animals that have gastrointestinal problems might need to have fecal exams more frequently. Ask your vet how often you should bring your dog's stool sample in for a fecal exam. 


A urinalysis is a simple diagnostic test performed at our pet laboratory that determines the physical and chemical properties of urine. It is primarily used to evaluate the health of the kidneys and urinary system, but it can also reveal issues with other organ systems. All senior dogs eight years of age and older should have a yearly urinalysis. A urinalysis may also be recommended if your dog has increased water intake, increased frequency of urination, or visible blood in the urine.

There are four main parts to a urinalysis:

  • Assess appearance: color and turbidity (cloudiness).
  • Measure the concentration (also known as the density) of the urine.
  • Measure pH (acidity) and analyze the chemical composition of the urine.
  • Examine the cells and solid material (urine sediment) present in the urine using a microscope.

Urine samples should be read within 30 minutes of the collection because other factors (such as crystals, bacteria, and cells) can alter the composition (dissolve or multiply).

Cells & Solid Material (Urine Sediment)

Some of the cells that might be found in your dog's urine can include:

    • Red Blood Cells
    • White Blood Cells
    • Protein
    • Sugar
    • Ketones
    • Bilirubin
    • Urobilinogen
    • Blood
    • Crystals
    • Bacteria
    • Tissue Cells

CBC (Complete Blood Count)

A complete blood count (CBC) and complete blood chemistry panel, including electrolytes and urinalysis, are common vet lab tests. The CBC identifies whether there is anemia, inflammation, or infection present. It can also indicate immune system response and blood clotting ability.

The chemistry panel and electrolytes tell your vet whether your dog’s liver, kidneys, and pancreas are working as they should.

This important veterinary laboratory work can also detect and help to identify complex issues within a dog’s internal systems. For example, blood tests for dogs can detect whether internal or environmental stimuli are causing hormonal-chemical responses. This tells a veterinarian there may be a potential problem with the dog’s endocrine system.

A CBC reveals detailed information, including:

  • Hematocrit (HCT): With this test, we can identify the percentage of red blood cells to detect hydration or anemia.
  • Hemoglobin and mean corpuscular hemoglobin concentration (Hb and MCHC): These are pigments of red blood cells that carry oxygen.
  • White blood cell count (WBC): With this test, we measure the body’s immune cells. Certain diseases or infections can cause WBC to increase or decrease.
  • Granulocytes and lymphocytes/monocytes (GRANS and L/M): These are specific types of white blood cells.
  • Eosinophils (EOS): These are a specific type of white blood cells that can indicate health conditions due to allergies or parasites.
  • Platelet count: (PLT): This test measures cells that form blood clots.
  • Reticulocytes (RETICS): High levels of immature red blood cells can point to regenerative anemia.
  • Fibrinogen (FIBR): We are able to gain important information about blood clotting from this test. High levels can indicate a dog is 30 to 40 days pregnant.
What Blood Chemistries Reveal (Blood Serum Test):

Blood chemistries (blood serum tests) give us insight into a dog’s organ function (liver, kidneys, and pancreas), hormone levels, electrolyte status, and more.

The test can be used to assess the health of older dogs, do general health assessments before anesthesia, or monitor dogs receiving long-term medications.

These tests also help us evaluate senior dogs’ health and those with symptoms of diseases (such as Addison’s, diabetes, kidney diseases, or others), diarrhea, vomiting, or toxin exposure.

We will be able to then combine physical treatment with medications from our St. Louis veterinary pharmacy to help manage your dog's condition.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.

If your vet has ordered a series of laboratory tests and you would like to learn more about their purpose, please contact our St. Louis vets to schedule a veterinary visit and diagnostic imaging.

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Animal Emergency Clinic is an after-hours emergency animal hospital providing urgent care to cats and dogs from St. Louis and surrounding areas. Contact us right away if you are experiencing a veterinary emergency.

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