White Blood Cell Disorders of Dogs

ByR. Darren Wood, DVM, DVSc, DACVP, Department of Pathobiology, Ontario Veterinary College, University of Guelph
Reviewed/Revised Dec 2017

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 of white 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 of white 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.

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 the number 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 of the 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.

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