The complete blood count measures the number of cells of different types circulating in the bloodstream. There are three major types of blood cells in circulation; red blood cells (RBC); white blood cells (WBC) and platelets.
Red blood cells are produced in the bone marrow, which is the soft centre of bones. RBC’s pick up oxygen brought into the body by the lungs, and bring that oxygen to cells throughout the body.
The complete blood count also includes a measure of haemoglobin, which is the actual substance in the red blood cell that carries oxygen.
Basophils (Bas) – are not well understood but they are involved in long-term allergic reactions such as asthma or skin allergies. It is a component of Granulocytes and is calculated as a % of WBC.
Blood Cell Count (RBC) – is the total number of red blood cells.
Eosinophils (Eos) – are normally 1% to 4% of WBC’s. They are involved with reactions to parasites (flea infestation); allergies; inflammation of the GI, urogenital or respiratory tract; or inflammation of the skin.
Haemoglobin (HGB) – is the actual carrier of the oxygen on the red blood cell. It is a measurement of the red cell mass.
Hematocrit (HCT) – measures the percentage of blood volume taken up by the red blood cells.
Lymphocytes (Lymphs) – are white blood cells produced in the lymph glands of the body. Lymphocytes fight infection and produce antibodies against infectious agents.
Lymphopenia – is a decrease in the number of proportion of lymphocytes (one of the white blood cells) in the blood.
Mean Corpuscular Haemoglobin (MCH) and Mean Corpuscular Haemoglobin Concentration (MCHC) – measure the average concentration of haemoglobin in erythrocytes. The MCH is calculated by dividing total haemoglobin by the total number of red blood cells.
Mean Corpuscular Volume (MCV) – measures the average volume (size) of individual red blood cells. A low MCV means that the cells are smaller than normal. This is usually caused by an iron deficiency or chronic disease.
Mean Platelet Volume (MPV) – is a measurement of the average size of platelets found in blood.
Monocytes or Macrophages (Monos) – make up 2% to 8% of WBC’s. They fight infection by “eating” germs and telling the immune system what germs they have found.
Neutrophils or Polymorphonuclear cells (Polys) – is the most common type of white blood cells and cause the body to fight bacterial infections.
Neutrophils can be decreased in pets with bone marrow disease, in some viral diseases and in some pets receiving cancer chemotherapy drugs. Neutrophils are increased in pets with inflammation or infection of any part of the body and in pets receiving Prednisone or other cortisone type drugs.
Packed Cell Volume (PCV) – is another measure of red blood cells. A small amount of blood is placed in a tiny glass tube and spun in a centrifuge. The blood cells pack to the bottom of the tube and the fluid floats on top.
The PCV is the percent of blood that is cells, compared to the total volume of blood. In normal dogs, 40–50% of the blood is made up of blood cells and the remainder is fluid.
Platelets (PT) – are the third type of blood cell examined in CBC, which are produced in the bone marrow and are involved in the process of making blood clot.
Red blood cells (RBC) – are produced by the bone marrow, and are responsible for carrying oxygen throughout the body. This is measured by three main tests.
Red Blood Cell Distribution Width (RDW) – is a measure of the variation of red blood cell (RBC) width that is reported as part of a standard complete blood count.
White Blood Cells (also called Leukocytes) – are produced in the bone marrow and are important for the immune system as they help fight infections in the body.
White Blood Cell Count (WBC) – is the total number of white blood cells. A high WBC usually means that the body is fighting an infection. A very low WBC can be caused by problems with the bone marrow.