Skip to content

What blood tests are done on pets?

If your pet is ill or going to have surgery, our vets will often want to carry out blood tests. But do you know what they are, and what we’re looking for?

Informative image: blood tubes - Kingsteignton Vet Group

There are three main reasons we’ll do blood tests on our patients. Firstly, if they’re apparently healthy, but we’re going to do an operation - this is mainly in older animals, and is called a pre-op blood test. The second reason is if they’re unwell, and we don’t know why - a complete or comprehensive blood test, also known as a blood panel, will give us more information to help us figure out why they’re ill and (hopefully) how bad it is.

Finally, if we suspect a specific disease, we may carry out one or more specialised tests to rule in or out that particular condition - we may be able to do these in our own practice lab, but often the more specialist tests have to be sent away to an external laboratory.

Biochemistry Tests

The commonly used tests are:
●    Blood Glucose (GLUC) - high glucose may mean diabetes mellitus or stress; low glucose usually means the blood tube has been left lying around for a while (!) but may also indicate insulin overdose
●    Urea (BUN) - a test for kidney function - higher means worse function; and an excessively low urea may suggest liver failure
●    Creatinine (CREA) - a test for kidney function - higher means worse function
●    Alkaline Phosphatase (ALKP) - a liver enzyme that is increased if bile stops flowing through the liver, but is also increased by certain drugs and bone diseases
●    Alanine AminoTransferase (ALT) - a liver enzyme that is increased by liver cell damage
●    Bilirubin (BILI) - a marker of liver function and red blood cell health (high bilirubin causes jaundice)
●    Albumin (ALB) - the main protein in the blood, low levels may mean liver failure, kidney or gut disease or severe burns; high levels usually indicate jaundice.
●    Globulin (GLOB) - immune proteins in the blood, elevated in chronic infections or inflammatory diseases.
●    Total Protein (TP) - the total protein, globulin plus albumin
●    Calcium - an important electrolyte associated with muscle, nerve and heart function; also useful as a marker for some hormonal and bone diseases, and tends to be elevated in some cancers (“Hypercalcaemia of Malignancy”)
●    Sodium - one of the main electrolytes in the blood
●    Potassium - one of the main electrolytes in the blood

Haematology Tests

The normal haematology tests are:
●    Packed Cell Volume (PCV) - the total percentage of cells in the blood; a useful marker for anaemia (if low) and dehydration (if high).
●    Red Blood Cells (RBC) - the number of oxygen-carrying red blood cells present in each ml of blood.
●    Mean Corpuscular Volume (MCV) - the average size of the red blood cells: young, immature cells are larger than old, dying ones, so this gives an indication of how well the body is making new red blood cells.
●    Mean Corpuscular Haemoglobin (MCH) - how much haemoglobin there is in each cell, a useful marker of some mineral and vitamin deficiencies.
●    Haemoglobin (Hb) - the amount of iron in the blood.
●    Platelets (PLAT) - how many platelets, the clotting cells, there are in the blood. Sadly, this test is notoriously inaccurate in dogs and cats, so we’ll often check it by counting under a microscope!
●    Leukocytes (LEUK) - the number of white blood cells, for fighting infection, in the bloodstream.
●    Granulocytes (GRAN) - the number of white blood cells that have granules in them; this does not include lymphocytes (which produce antibodies and kill infected cells) but does cover eosinophils and basophils (for fighting parasites) and...
●    Neutrophils (NEUT) - the cell responsible for fighting acute onset infections; in an infection, the numbers will drop (as they all rush off to fight it) and then rise dramatically (as the body makes extra ones).
●    Thyroid Hormone (T4) - used mainly in cats to test for hyperthyroidism; occasionally in dogs for hypothyroidism.
●    Cholesterol (CHOL) - usually in cats, to test for fat in the blood, often a marker of liver problems.

Pre-Op Blood Test

This usually includes a Biochemistry Panel - often a “pre-op panel”, containing 5 or 6 different tests. This will give us a rough idea of how well their kidneys and liver are working, which are the organs most likely to need extra support during surgery. It will also contain a basic Haematology Analysis to let us know if they are anaemic, and how well their immune system is working.

Comprehensive Blood Test

This generally contains a more detailed Biochem panel, usually with 12 tests in dogs and 14 in cats; and a Complete Blood Count - a form of haematology analysis that looks at red blood cells, white blood cells and platelets in the blood.

Specific Tests

These vary depending on what the condition is or may be, and there are many hundreds, if not thousands, available for dogs and cats alone! The more common ones include…
●    Canine Pancreas-specific Lipase (cPL) - a test for pancreatitis in dogs
●    Feline Pancreas-specific Lipase (fPL) - a test for pancreatitis in cats
●    Trypsin-Like Immunoreactivity (TLI) - a test for pancreatic insufficiency (EPI)
●    Coombes Test - a test for immune anaemia
●    Fructosamine - a test for diabetes mellitus

As you can see, we can learn a lot about your pet’s health from their blood! Give us a ring if you’d like to know more.