Lab work is typically the same thing as blood work, which involves drawing a blood sample. We're often using the jugular vein, which is a vein that runs just under the neck. Other times, we may use a leg vein, a front leg vein, or a back leg vein, depending on what tests we're running. It allows us to take your cat's blood sample and put it through our analyzers here, and compare it to what the normal values are for a normal cat. That's how we detect disease. Also, lab work sometimes involves us getting a urine sample, which can be collected through a special cat litter or through a small gauge needle that we put in the bladder to retrieve the sample.
Having a baseline lab test is important, especially early on, because it gives you a timeline of when things may or may not have occurred. For instance, if your cat's blood work was normal a year ago and this year it wasn't, then that gives us a little bit of an indication about when and where the problem could have happened. So having baseline blood work is always a good foundation to have for your pet's health assessment.
What specific things are being looked at using my cat's blood work, and what health conditions can they help detect?
Blood work involves three to four different procedures. One is a CBC, which assesses your red and white blood cell counts—it looks at your platelet counts as well as certain cells within the white blood cell count line. The other component is typically a blood chemistry. A chemistry looks at values that are related to your kidney function, your liver function, your protein levels related to your pancreatic function, and often a thyroid level. Then, as we spoke about earlier, a urinalysis tells us whether there are bacteria in urine or red or white blood cells or potentially crystals or other types of casts. Aside from those, there are other tests that we can run to detect certain viruses. We can diagnose kidney failure, liver failure, diabetes, thyroid disease, and viral diseases, such as feline immunodeficiency virus or feline leukemia virus—all with bloodwork. And then, past that, we can detect if there are low protein levels or whether there are issues involving the electrolytes, calcium deficiencies, or excesses.
When Will A Veterinarian Order Blood Tests For Cats?
Sometimes in the case of an eye or ear infection, your feline friend's medical condition affords a veterinarian the opportunity for a relatively straightforward diagnosis. However, other times there is a need for further examination. In such cases, your veterinarian may order feline blood tests to aid in his or her investigation. The following situations can result in the need for blood tests for cats:
- On the first veterinary visit: This is recommended to establish healthy baseline tests and also to check for any congenital abnormalities or potential concerns.
- During semi-annual wellness exams: Your veterinarian may suggest blood tests as part of a thorough physical examination because cat blood work, along with other bodily fluids like urine, can help identify conditions the examination portion of a physical cannot.
- If a cat seems not quite right: Cat blood tests are indicated for cats who are not displaying any overt signs of illness, disease, or injury but are acting abnormally.
- Pre-surgical tests: Cat blood work is used to determine the general health of the liver and kidneys, which helps a veterinarian select the safest form of anesthesia. Blood work can also help determine the surgical risk level in infirmed, elderly, or injured cats.
- During senior wellness exams: Cat blood tests are usually recommended for mature, senior, and geriatric cats as part of their periodic wellness exams. These are extremely beneficial, and we often see senior cats return to a more youthful state of being when blood tests identify an issue that can be easily treated.
Types of Feline Blood Work
- Feline Leukemia–Feline Immunodeficiency Virus: This is a common test for kittens and cats, especially those coming from unknown origins. These viruses are interspecies contagious and life threatening, so we recommend feline blood work if you adopt, find, or take in a new kitten or cat.
- Complete Blood Count (CBC): We analyze cat blood work to assess features of the blood, including red and white cell count, immunity status, and the measure of hemoglobin, which is the actual substance in red blood cells that carries oxygen. We also examine hydration status, anemia, infection, blood clotting ability, and immune system response. A CBC is essential for cats that have symptoms like fever, vomiting, diarrhea, weakness, pale gums, or loss of appetite. A CBC can also detect bleeding disorders or other unseen abnormalities as part of a pre-surgery risk assessment.
- Blood Serum Chemistry: We analyze cat blood work to evaluate organ function, electrolyte status, hormone levels, and more. These tests are important for evaluating the health of older cats, cats with signs of vomiting, diarrhea or toxin exposure, cats receiving long-term medications, and general health before anesthesia.
- Total Thyroid Level: We analyze cat blood work for hyperthyroidism as well as for the reverse condition euthyroidism, or low thyroid function, which can indicate disease in a cat’s body.
Additionally, our in-house laboratory can process and analyze:
- Stool Samples
Understanding Your Cat's Blood Work
After we process and analyze a cat blood work sample, the next step is to help you fully understand any abnormal results. Your cat's blood work allows our veterinarians to evaluate the following:
- Albumin (ALB): This is a serum protein that helps evaluate hydration, hemorrhage, and intestinal, liver, and kidney disease.
- Alkaline phosphatase (ALKP): Elevations in this test may indicate liver damage, Cushing’s disease, or active bone growth in a young cat. This test is especially significant in cats.
- Alanine aminotansferase (ALT): This test may determine active liver damage, but it does not indicate the cause.
- Amylase (AMYL): Elevations in this test indicate pancreatitis or kidney disease.
- Aspartate aminotransferase (AST): Increases in this test may indicate liver, heart, or skeletal muscle damage.
- Blood urea nitrogen (BUN): This test determines kidney function. An increased level is called azotemia and can be caused by kidney, liver, and heart disease as well as urethral obstruction, shock, or dehydration.
- Calcium (Ca): Changes in the normal level of this test can indicate a variety of diseases. Tumors, hyperparathyroidism, kidney disease, and low albumin are just a few of the conditions that alter serum calcium.
- Cholesterol (CHOL): This test is used to supplement a diagnosis of hypothyroidism, liver disease, Cushing’s disease, or diabetes mellitus.
- Chloride (Cl): Chloride is an electrolyte that when lost typically leads to symptoms like vomiting or illnesses such as Addison’s disease. Elevations often indicate dehydration.
- Cortisol (CORT): Cortisol is a hormone that is measured in tests for Cushing’s disease (the low-dose dexamethasone suppression test) and Addison’s disease (ACTH stimulation test).
- Creatinine (CREA): This test reveals kidney function and helps distinguish between kidney-related and non-kidney-related causes of elevated BUN.
- Gamma glutamyl transferase (GGT): This is an enzyme that indicates liver disease or corticosteroid excess.
- Globulin (GLOB): This is a blood protein that often increases with chronic inflammation and certain disease states.
- Glucose (GLU): Glucose is a blood sugar. Elevated levels may indicate diabetes mellitus. Low levels can cause collapse, seizures, or coma.
- Potassium (K): This is an electrolyte. Low levels typically lead to symptoms such as vomiting, diarrhea, or excessive urination. Increased levels may indicate kidney failure, Addison’s disease, dehydration, or urethral obstruction. High levels can lead to cardiac arrest.
- Lipase (LIP): Lipase is an enzyme that may indicate pancreatitis.
- Sodium (Na): Sodium is an electrolyte. Low levels may lead to vomiting, diarrhea, kidney disease, and Addison’s disease. This test helps indicate hydration status.
- Phosphorus (PHOS): Elevations in this test are often associated with kidney disease, hyperthyroidism, and bleeding disorders.
- Total bilirubin (TBIL): Elevations in this test may indicate liver or hemolytic disease. This test helps identify bile duct problems and certain types of anemia.
- Total protein: This test indicates hydration status and provides additional information about the liver, kidneys, and infectious diseases.
- Thyroxine (T4): Thyroxine is a thyroid hormone. High levels indicate hyperthyroidism in cats.
Not always. We see sick cats with normal blood work. That's why it's always essential to do a good physical exam. Using our hands is often better than our tests sometimes in determining what might be going on. And there are other times when we may need imaging, such as x-ray or ultrasound.
Early detection is crucial because it gives us the best chance we have to, one, detect disease. Two, if we detect disease, it gives us the best opportunity to prevent the progression of it if we can. It also allows us to use as many modalities of treatment available to us to help improve the quality of life and longevity of the life.
If you still have other questions and you'd like to reach out to us, you can call us directly at (615) 283-9040, you can email us, or you can reach out on Facebook. But please do reach out, and we'll get back to you as soon as we can.