What is a High White Blood Cell Count in Cats? Causes, Symptoms, and Treatments of This Condition

A Cat Laying On The Floor With His Paw Raised
expert or vet photo
vet verified PetCareRx Staff Veterinarian DVM

White blood cells fight off infections in your cat's body. If your cat has a high white blood cell count, that is a clear sign that something is wrong.

Running periodic complete blood counts on your cat may be one of the best things you can do for their overall health. After all, a high white blood cell count in cats could point to a potassium deficiency or even cancer.

A complete blood count determines the number and types of blood cells present, specifically red blood cells, white blood cells, and platelets. A normal white blood cell count in cats typically ranges from 4,900 to 20,000 per microliter of blood. However, that “normal” range could vary depending on the age of the cat.

White blood cells, also known as leukocytes, defend the body against viruses, bacteria, and fungi. Your cat’s blood contains a militia of white blood cells known as the differential, which take the form of neutrophils, eosinophils, basophils, lymphocytes, and monocytes.

  • Neutrophils and eosinophils, which are produced in the cat’s bone marrow, are released into the bloodstream to destroy bacteria.
  • Basophils are also produced in the bone marrow, but researchers aren’t entirely clear as to their main purpose.
  • Lymphocytes are produced in the cat's lymph nodes and spleen.
  • Monocytes are stored in the spleen and bone marrow.

Your cat doesn’t necessarily need to be exhibiting signs of an illness for your vet to recommend a complete blood count. Some vets like to run a count during wellness exams to determine a normal range for your cat or to monitor overall health.

Why Would a Cat Have a High Blood Cell Count?

  • Bacterial or fungal infections can cause neutrophil levels to increase.
  • Stress can cause neutrophil levels to increase.
  • Parasites, such as heartworm, can cause eosinophil and basophil levels to increase.
  • Allergic reactions can cause eosinophil levels to increase.
  • Autoimmune diseases with occurrences of inflammation can cause lymphocyte levels to increase.
  • Various types of cancer or viral infections can cause lymphocyte and monocyte levels to increase.
  • Kidney failure can cause overall white blood cell levels to increase.
  • Potassium deficiencies can cause white blood cell levels to increase.
  • Medications, such as corticosteroids, can cause white blood cell levels to increase.

How You’ll Know if Something is Wrong

Symptoms are typically related to the cause of the high white blood cell count.

  • If the cause is an infection, symptoms will typically appear as fever, lack of appetite, moodiness, and fatigue. If the infection is external, there may be a rash, wound, or abscess.
  • If the cause is parasites, such as heartworm, symptoms will appear as coughing, rapid breathing, vomiting, fatigue, and weight loss.
  • If the cause is an autoimmune disease, the symptoms will vary depending on the disease. Swollen joints may be present, or hair loss and ulcers on the skin, as well as fever and fatigue.
  • If the cause is lymphoma or other types of cancer, symptoms will typically appear as swollen lymph nodes, tumors, weight loss, frequent urination, increased thirst, and fatigue.
  • If the cause is kidney failure, symptoms typically do not present themselves until considerable damage is done to the organ. When symptoms do appear, they appear as frequent urination, increased thirst, weight loss, fatigue, ulcers on the gums and tongue, vomiting, and diarrhea.
  • If the cause is allergies, symptoms will appear as continuous itching and scratching.
  • If the cause is a potassium deficiency, symptoms will appear as fatigue, weight loss, frequent urination, and vomiting.
  • If the cause is stress, symptoms will likely appear as moodiness, aggression, decrease in social interaction, and decreased appetite.

Treatment Options

If a complete blood count shows that your cat’s white blood cell levels are high, there are a number of treatments your vet may recommend tailored to the cause of the high blood cell count.

Infections, autoimmune diseases, lymphoma, kidney failure, allergies, potassium deficiencies, and stress will all be treated with the best option for your pet.

When it comes to heartworms, there are no products in the United States approved for their treatment in cats. That’s why preventative medications are so important. In most cases, cats fight off the infection on their own, but you should still see your vet.

As the condition is treated, the results of follow-up blood tests should show white blood cell counts leveling out to the recommended range.

Frequently Asked Questions

Can kidney disease cause a high white blood cell count in cats?

Yes. Veterinarians say that kidney disease can cause increased white blood cells due to infection or inflammation. The veterinarian will take a complete blood count (CBC) test that analyzes the single hematology sample that evaluates the red blood cells, white blood cells, and platelet numbers.

Can stress cause a high white blood cell count?

Yes. Carrington says that stress increases the white blood cell count. This indicates a connection between elevated stress levels and the body's production of what are known as inflammatory leukocytes, a particular variety of white blood cells. Normally, inflammatory leukocytes are the body's defense system against infection and disease.

What is a normal white blood cell count for a cat?

PetCareRX says that a normal white blood cell count in cats typically ranges from 5,500 to 19,500 per microliter of blood. The veterinarian will run a complete blood count to determine your cat's white blood cell count.

What do high lymphocytes mean in cats?

Veterinarians globally see that increased numbers of granular lymphocytes may indicate a viral infection, such as lymphocytosis. They may say that cats may recover from a postvaccination from an immune-mediated disorder.
More on Cat Health

Caring for a Cat With Cancer at Home
Food to Treat Kidney Disease in Cats and Dogs
Antibiotics for Cats

This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.

Was this article helpful?
General Allergies Kidney Failure Heartworm

You May Also Like