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Cat Blood Tests Results, Explained

Blood tests for cats are a valuable tool in most veterinary clinics. Our Blountville vets explain why blood tests for cats are important and what each test result might mean.

Blood Test For Cats

When your veterinarian suggests blood work for your cat, you may not be sure what they are looking for. Even the most experienced pet owners can be terrified of not knowing why their cat needs a medical procedure and what the results mean.

 Below are some of the common blood tests done on cats and what they tell the veterinarian.

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

The relationship between creatinine levels and kidney function is more direct. High levels suggest that kidney disease may be forming and that the cat's kidneys are struggling to remove creatinine from the body.

Alanine Aminotransferase (ALT) & Bilirubin

Regular blood panels frequently contain blood chemistries like ALT and bilirubin. They primarily serve as a measure of the health of the liver, and if they are abnormally high, this usually denotes liver dysfunction.


When a cat is suspected of having diabetes mellitus, the glucose level is typically checked. In this case, the glucose level will be quite high. An important piece of information about a cat's general health can also be obtained by a veterinarian from low blood sugar levels.

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

    In kittens and at regular intervals throughout adulthood, FELV and FIV are routinely tested. Because these viruses are life-threatening and cannot be cured once your cat has been infected, it is critical to keep track of your cat's status in relation to them.

      Thyroxine (T4)

      T4 levels in cats are usually checked as they get older. A high T4 level could be the first sign of hyperthyroidism, a common condition in cats. High thyroid levels in cats can cause a variety of symptoms, including increased appetite, weight loss, eating non-food items or a desire for more human food, and increased vomiting.


      Electrolyte levels, which include potassium, sodium, and chloride, can tell a veterinarian a lot about a cat's health, including hydration and organ function, particularly the kidneys. Electrolyte imbalances in cats can cause a variety of symptoms, including heart arrhythmias and muscle weakness.

      Why Your Vet Might Suggest Blood Work

      There a 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, along with 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 blood work 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.

      What Can Be Learned From Your Cats Blood Test

      The results of feline blood tests are essential to helping veterinarians diagnose and treat medical conditions both within the blood itself, as well as in organs such as the kidney and liver. During a blood test for cats, various chemicals in the bloodstream are analyzed. Some examples are:

      • Cat blood tests can indicate a deficiency in albumin levels, which indicates 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.

      Once the connection has been made, we can order any additional feline bloodwork or treatments required for the condition's diagnosis and treatment. The ability to detect, identify, diagnose, treat, and ultimately prevent illness or disease makes feline blood tests a very important tool in a veterinarian's toolbox.

      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 is displaying abnormal behavior, maybe a blood test is in order. Don't hesitate to contact our Blountville vets to schedule an appointment today.

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      Airport Pet Emergency Clinic is open weekday evenings, overnight, weekends and holidays to provide your pet with urgent care when needed. Our experienced Blountville vets are passionate about caring for companion animals.

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