Skip to Main Content
Ask About Financing

Understanding Blood Tests for Cats

Blood work provides our veterinary team with vital information about your cat's internal health. Here, our Los Angeles vets explain the importance of blood tests for cats, the common types and what we can learn from their bloodwork.

What are the most common types of blood tests for cats?

You may not be sure what your veterinarian is looking for when they suggest blood work for your cat. Not knowing the reasons behind their cat's medical procedure and the implications of the results can be a source of great anxiety for even the most seasoned pet owners.

The veterinarian can learn valuable information by conducting common blood tests on cats.

Complete Blood Count (CBC)

A CBC measures and examines a cat's blood cells. It gives the veterinarian a wealth of information. Some of these include:

  • Red blood cell (RBC) counts, proportions, and health - RBCs carry oxygen, iron, and other nutrients around the body.
  • White blood cell (WBC) counts, proportions, and health - WBCs help fight inflammation, infection, cancer cells, and parasitic intruders.
  • Platelet counts and health - Platelets control blood clotting.

A CBC can tell a veterinarian if a cat is anemic, dehydrated, fighting off inflammation or an infection, and whether your cat has internal bleeding.

BUN & Creatinine

BUN and creatinine, two blood chemistries, are routinely measured as part of larger blood panels. A high BUN level could indicate dehydration, kidney dysfunction, or a liver problem.

Kidney function has a stronger correlation with creatinine levels. When the cat's kidneys struggle to eliminate creatinine from the body, it suggests the possibility of kidney disease.

Alanine Aminotransferase (ALT) & Bilirubin

Routine blood panels often include blood chemistries like ALT and bilirubin. They mostly indicate liver health, and if they are unusually high, they usually suggest liver dysfunction.


Testing glucose levels is a common way to determine if a cat has diabetes mellitus. If the cat does have diabetes, the glucose level will be significantly elevated. Analyzing low blood sugar levels can give a veterinarian valuable insights into a cat's overall health.

    Feline Leukemia Virus (FeLV) & Feline Immunodeficiency Virus (FIV)

    FeLV and FIV are standard tests for both kittens and adult cats. Life-threatening viruses pose a serious risk to your cat's health and cannot be cured once infected. Therefore, closely monitoring your cat's condition with these viruses is crucial.

      Thyroxine (T4)

      As cats age, it is common to monitor their T4 levels. A high T4 level may indicate hyperthyroidism, a common internal medicine condition in cats. Cats with high thyroid levels may experience a range of symptoms, including increased appetite, weight loss, consumption of non-food items or a desire for more human food, and increased vomiting.


      By analyzing electrolyte levels, including potassium, sodium, and chloride, a veterinarian can gain valuable insights into a cat's health, such as hydration levels and organ function, particularly the kidneys. Cats may experience various symptoms due to electrolyte imbalances, such as heart arrhythmias and muscle weakness.

      When will a cat have bloodwork performed?

      There are many reasons your vet might suggest bloodwork for your cat. Here are the most common reasons:

      It's your cat's first exam - We recommend blood work at the time of your cat's first exam because it helps us establish baseline health, check for any congenital abnormalities or potential concerns, and help us form an individual wellness plan for your cat.

      During semi-annual and annual wellness exams - Cat blood tests are usually recommended for all life stages, from kittens to geriatric cats, as part of their routine wellness checkups. These are extremely beneficial in our mature patients, as we often see cats' health and happiness return to normal when blood tests catch illness early. Cat bloodwork and other bodily fluids like urine can help identify conditions the examination portion of a physical cannot.

      If a cat seems sick - Cat blood tests are suitable for cats that are not displaying any overt signs of illness, disease, or injury but are acting abnormally.

      Before surgery - Cat bloodwork is used to determine the general health of the liver, kidneys, and other organs, which helps a veterinarian select the safest form of anesthesia. Bloodwork can also help determine the surgical risk level in all cats, especially elderly or injured patients.

      Cat Blood Test Results, Explained

      The results of feline blood tests are essential to helping veterinarians diagnose and treat medical conditions in the blood and in organs such as the kidneys and liver. During a blood test for cats, various chemicals in the bloodstream are analyzed.

      Some examples of what we see when we review the results of your cat's blood tests are:

      • Cat blood tests can indicate a deficiency in albumin levels, which means a possible liver issue because albumin is produced in the liver or intestinal or kidney issues, as albumin can be lost if these are diseased.
      • Blood tests for cats can detect abnormal hormonal-chemical responses to environmental and internal stimuli, which indicates a potential issue with the patient's endocrine system.

      After establishing a link, we can easily order any necessary feline bloodwork or procedures to diagnose and treat the condition. Feline blood tests play a crucial role in a veterinarian's toolbox. They help detect, identify, diagnose, treat, and prevent cat illness or disease.

      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 cat displays concerning symptoms, our vets can diagnose and treat the illness. Don't hesitate to contact our Los Angeles vets to schedule an appointment today.

      Looking for a vet in Los Angeles?

      Our veterinarians are passionate about caring for Los Angeles companion animals. Get in touch today to request an appointment for your pet. 

      Contact Us

      Book Online (213) 201-7900