Types of Diagnostic Tests for Pets

Diagnostic tests play a crucial role in veterinary care, but it's natural to feel anxious when your pet requires them. Our Seattle vets are here to tell you all about diagnostic testing for pets. 

Why Do Dogs Need Lab Work?

Veterinary lab work comes in various forms and is typically done when we need to find out why your pet is sick. It's not just for illnesses but is most often used to identify the cause of a health problem or check if there's any illness present. For instance, it helps detect issues like heartworm disease or intestinal worms, which might not be obvious. So, we perform veterinary lab tests to see if these problems exist in your pet.

What Are The Different Types of Lab Work?

While there are so many different types of lab tests available, you will more often hear the umbrella term "lab work" as an all-encompassing term. 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 Seattle vet lab to provide the most accurate information possible:

Heartworm Tests

This disease usually comes from mosquito bites. When these mosquitoes bite, they can transfer a tiny worm called Dirofilaria immitis.

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

The tricky thing is you won't see signs of this disease in your dogs and cats until it's quite advanced. The most common signs are a swollen belly, coughing, tiredness, weight loss, and trouble 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.

It's much better to stop the illness from happening in the first place because treating it can be harmful to your pet and expensive. Treatment needs lots of vet visits, hospital stays, X-rays, blood tests, and injections. Our vets in Seattle recommend preventing heartworm disease.

However, if your cat or dog is diagnosed with heartworm, 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 a yearly check-up for your pet's health. Your vet uses a lab to examine a small sample of your pet's poop under a microscope. This helps find and treat infections that could affect your pet's well-being and even yours.

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.

These parasites usually hide in your pet's gut. So, fecal exams are the best way to detect them.

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


A urinalysis is a basic test done in our pet lab to check the properties of urine. It helps us see how the kidneys and urinary system are doing and can spot problems with other organs. Senior pets should get this test every year. We might also suggest it if your pet drinks more water, pee more often, or has blood in their 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 or cat'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 CBC checks for anemia, inflammation, or infection and provides insights into the immune system and blood clotting.

This important veterinary laboratory work can also detect and help identify complex issues within a pet'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 pet's endocrine system.

In short, CBC gives detailed information about:

  • 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 specific types 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 or cat's organ function (liver, kidneys, and pancreas), hormone levels, electrolyte status, and more.

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

These tests are also useful for evaluating the health of senior pets and those showing signs of diseases like Addison's, diabetes, kidney issues, and more.

We can combine physical treatment with medication from our Seattle veterinary pharmacy to help manage your pet'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 pet is not feeling well, contact our Seattle vets today to book an appointment. We can perform a diagnosis test to get to the bottom of the issue.