One of the most common blood tests run in dogs is a complete blood count, also known as a full blood count. This blood count mainly focuses on determining the number and types of blood cells present in the blood. The cells that are looked at in a complete blood count are red blood cells, white blood cells and platelets. Abnormal counts of any of these cells may be therefore indicative of various conditions.
White blood cells, also often referred to as leukocytes, act as a brave company of soldiers whose main goal is to defend the dog's body from viruses, bacteria or fungi. Their normal numbers in a dog according to Peteducation.com range between 6,000 and 17,000 per microliter.
Types of White Blood Cells
A differential white blood cell count may further go into depth and determine exactly what types of white blood cells are elevated. There are indeed several types of white blood cells such as neutrophils, eosinophils, basophils, lymphocytes and monocytes.
Neutrophils are created in the dog's bone marrow and then released into the bloodstream. When they are young, they present a single-lobed nucleus and are referred to as 'bands'. As they mature, they assume a multi-lobed nucleus and are called 'segs'. Their main duty is to 'engulf and destroy' bacteria. Elevated numbers of neutrophils are therefore indicative of infection. At times, high levels however may be also present in highly stressed dogs. The normal number of mature neutrophils range between 3,000 to 12,000 per microliter of blood while the number of young neutrophils range between 100 to 300 per microliter.
Eosinophils are also produced in the bone marrow and they play the same role of neutrophils: engulfing any foreign particles found in the dog's body.Their increase in number is often indicative of some form of infection due to parasites or allergies. Their normal range is between 100 to 1200 per microliter.
Lymphocytes are produced by the dog's lymph nodes and spleen. They are further divided into two categories: B cells and T cells. B cells tend to produce protein molecules which ultimately destroy any invading particles while T cells, on the other hand, help out other cells get rid of invading particles. Normal lymphocyte values range from 500 to 4,800 per microliter. An increase of lymphocytes may be indicative of a prolonged infection, an autoimmune disorder, or leukemia, an uncommon cancer of the blood.
Monocytes are finally the last type of white blood cells. They are stored in the spleen and bone marrow. Their normal values range between 100 to 1800 per microliter. Their numbers may increase when a dog is affected by leukemia.
The role of Basophils is yet to be understood. They too are produced by the bone marrow but they may or may not be present in the blood sample. At times, their presence may be indicative of heartworm disease.
As seen, there are a variety of causes for an increased number of white blood cells in dogs. At times, a high white blood count may prompt the veterinarian to run other diagnostic tests. Treatment is therefore aimed at bringing the values back to normal based on the veterinarian's findings.