Leukocytes, or white blood cells, include neutrophils, lymphocytes, monocytes, eosinophils, and basophils ( see White Blood Cells of Dogs). These cells vary with regard to where they are produced, how long they circulate in the bloodstream, and the factors that stimulate them into going in or out of the intricate network of blood vessels that branch out through the tissues of the body. The normal numbers of each type ofwhite blood cell also vary between species. Leukocytosis is an increase in the total number of circulating white blood cells; leukopenia is a decrease. In addition to an overall increase or decrease in white blood cells, increases or decreases in each type ofwhite blood cell can lead to—and help diagnose—disorders.
Leukograms are blood tests that count the number of different white blood cells circulating in the bloodstream. By counting the cells and examining their form, your veterinarian gains valuable information that can help diagnose a wide variety of disorders.
Disorders Related to Increased or Decreased White Blood Cells
Neutrophilia is an increase in the number of neutrophils in the bloodstream and is caused by inflammation. Structural changes in neutrophils may occur during severe inflammation and are referred to as toxic changes. Neutropenia is a decrease in the number of neutrophils in the bloodstream. It may occur due to the white blood cells sticking to the walls of damaged blood vessels, destruction of neutrophils, or reduced formation in the bone marrow. Neutropenia may occur in all species during overwhelming bacterial infections. Adverse reactions to drugs may result in neutropenia or even pancytopenia (a reduction in red and white blood cells and platelets).
Eosinophilia is an increase in the number of eosinophils, which are involved in allergic reactions and in controlling parasites. Increases are caused by substances that promote allergic reactions (for example, histamine) and by certain antibodies. Eosinophils increase during infections with parasites such as heartworms or fleas. Eosinophilia also may occur with inflammation of the intestines, kidneys, lungs, or skin. A decrease in eosinophils isknown as eosinopenia. It is a common reaction to stress or treatment with corticosteroids.
Basophils are rare in domestic animals. Basophils produce histamine and, like eosinophils, are involved in allergic reactions and combating parasites. Basophilia (an increase in basophils) is uncommon, but does occur in some dogs with heartworm disease.
Lymphocytosis is an increase in the number of lymphocytes in the bloodstream. It can be caused by certain hormones, stimulation of the immune system by infections, chronic diseases like arthritis, and leukemia, which is a cancer of the immune system. Lymphopenia is a decrease in the number of lymphocytes. Itis most commonly caused by corticosteroids (either those naturally occurring in the body or given as treatment for a disease). Lymphopenia may also be caused by other conditions, such as decreased production of lymphocytes, some viral infections, and hereditary diseases.
Monocytosis is an increase in monocytes and may be associated with longterm inflammation.
Leukemia and Lymphoma
Leukemia is a malignant cancer that is characterized by an increase in abnormal white blood cells in the bloodstream. Lymphoma is a related cancer of certain white blood cells that begins in a lymph node or other lymphoid tissue ( see Malignant Lymphoma in Dogs). Leukemia should be considered a potential cause when there is an increase in thenumber of white blood cells in the bloodstream.
Gray Collie Syndrome
This syndrome, also called cyclic hematopoiesis, is an inherited deficiency of the immune system that affects gray (but not merle) Collies. Signs of the disease include an extensive decrease of neutrophils that occurs in 12‑day cycles, overwhelming reoccurring bacterial infections, bleeding, and a pale coat and nose color. The start of this disease is thought to be a defect in the maturation ofthe cells that form red and white blood cells and platelets in the bone marrow. Blood cell growth factors and other hormones also have a cyclic pattern.
Affected puppies often die at birth or during their first week. Most dogs with the disease die by 6 months of age. Surviving dogs may be stunted and weak and develop serious bacterial infections during the periods when neutrophil numbers are low. They also develop amyloidosis, an accumulation of an abnormal protein called amyloid.
Your veterinarian can diagnose the disease based on the signs and results of blood tests. Treatment with proteins that stimulate the production of neutrophils in the bone marrow may provide temporary—but not longterm—improvement..
Pelger-Huët Anomaly
This inherited condition is caused by the failure of white blood cells to mature normally. White blood cell function is normal, and most animals do not have any signs of illness.
For More Information
Also see professional content regarding white blood cell disorders.
FAQs
What is an alarming white blood cell count in dogs? Abnormally low white blood cell counts in a dog are any value fewer than 3,000 cells per microliter on a complete blood count. As the body has neutrophils that don't travel in the bloodstream, how serious neutropenia is depends on more than just the number.
What causes elevated white blood cells in a dog? ›
WBC is an abbreviation for white blood cell count. These cells help fight infection and respond when an area of the body becomes inflamed. Elevated white blood cell counts indicate infection, inflammation and some forms of cancer or leukemia.
What are some white blood cell disorders? ›
Two major types of white blood cell disorders are proliferative disorders and leukopenias. In the proliferative disorders, there is an increase in the number of white blood cells. This increase is commonly a reaction due to infection, but may, less commonly, be related to some types of cancer.
What kills white blood cells in dogs? ›
Autoimmune disorders. Some autoimmune conditions can cause your dog's body to destroy their own white blood cells. Medications. Drugs such as trimethoprim, dipyrone, and methimazole have been known to decrease WBC levels.
What level of WBC is alarming? ›
A normal white blood cell count is generally about 4,500 to 11,000/μL. White blood cell counts that are too high or too low may be dangerous, depending on the cause. A high white blood cell count is called leukocytosis, which is generally diagnosed when white blood cell levels exceed 11,000/μL.
What is considered abnormal WBC count? ›
The normal number of WBCs in the blood is 4,500 to 11,000 WBCs per microliter (4.5 to 11.0 × 109/L). Normal value ranges may vary slightly among different labs. Some labs use different measurements or may test different specimens. Talk to your provider about your test results.
Can pancreatitis in dogs cause elevated white blood cells? ›
In severe cases, these signs can lead to shock and death. Laboratory tests often show increased white blood cell count, along with elevations in pancreatic and liver enzyme levels. Radiographs (x-rays) may show decreased detail in the area of the pancreas.
What causes high white blood cell count without infection? ›
Leukocytosis is most commonly caused by infection or inflammation. Other high white blood cell count causes may include: Excessive physical or emotional stress (such as fever, injury or surgery). Burns.
What disease causes overproduction of white blood cells? ›
On the flip side, when there is a malfunction or mutation in the bone marrow that results in an overproduction of white blood cells, it results in a condition known as chronic myelomonocytic leukemia (CMML). The most common symptoms of CMML include: Fatigue.
Which blood disorder is not treatable? ›
Polycythemia vera
This causes your blood to thicken and flow more slowly, putting you at risk for blood clots that can cause heart attacks or strokes. There is no known cure.
Some autoimmune diseases such as lupus or rheumatoid arthritis may cause an elevated white blood cell count.
What virus attacks white blood cells? ›
Diseases that can lower your white blood count include some types of cancer and HIV/AIDS, a viral disease that attacks white blood cells.
Can a dog survive with a low white blood cell count? ›
If infection is the primary cause, your dog may make a full recovery, as long as he survives the initial disease. The prognosis will depend on the diagnosis of a veterinarian. Leukopenia can be expensive to treat.
What would cause a high white blood cell count in dogs? ›
Any issue that creates enough inflammation, including a lot of immune mediated diseases (body's immune system attacks its own cells) can create high white blood cell counts. Even some cancers can cause high WBC counts.
What can I feed my dog to increase white blood cells? ›
Pro-immunity extras include red-bell peppers, berries (such as strawberries and blueberries), as well as spinach, carrots or kale. Many dogs will take these offerings as training treats, or they can be added to their meals. If you feel that your dog needs immune support beyond this level, consult your veterinarian.
What level of high WBC is concerning? ›
What's considered high in a white blood cell count varies from one lab to another. This is because laboratories set their own reference ranges based on the populations they serve. In general, for adults a count of more than 11,000 white blood cells in a microliter of blood is considered high.
What is a critically low WBC count? ›
A blood test that shows a WBC count of less than 4,000 per microliter (some labs say less than 4,500) could mean your body may not be able to fight infection the way it should. A low number is called leukopenia or neutropenia. Leukopenia can either be acute or chronic.
What is a severe WBC count in infection? ›
Normally the total WBC count for an adult ranges from 5,000 to 10,000/mm 3. Leukocytosis (WBC > 10,000/mm 3) can indicate infection, inflammation (possibly from allergies), tissue damage or burns, dehydration, thyroid storm, leukemia, stress, or steroid use.
