Anemia is defined by a decreased number of red blood cells (erythrocytes) and/or a lack of hemoglobin inside the blood.
Red blood cells are essential for transporting oxygen into the body and its organs. Therefore, decreased numbers of red blood cells, a.k.a. erythrocytes, cause symptoms such as fatigue, lethargy, and exercise intolerance. In more severe cases, breathing along with the animal's heart rate to become rapid. If no treatment is initiated, anemia can lead to shock and circulatory failure.
Anemia can be caused by excessive blood loss, i.e. after an accident. In animals suffering from tumors, tissue ruptures may cause bleeding into body cavities. Infectious agents such as babesia or leptospira, as well as poisoning can cause the destruction of erythrocytes and subsequent anemia, which is referred to as hemolytic anemia. In adult mammals, erythrocytes are produced in the bone marrow, while the rate of production is regulated through a hormone synthesized in the kidneys. Therefore conditions affecting either the bone or the kidneys can lead to decreased erythrocyte production and anemia, which is referred to as anaplastic anemia. In rare cases the immune system is producing antibodies against erythrocytes that lead to their destruction. This type of anemia is referred to as autoimmune hemolytic anemia.
Thorough clinical examination can reveal suspicious symptoms. Diagnosis is performed by taking and examining a blood sample, which can reveal evidence about the type and extent of the anemia. In cases where a large amount of blood is lost, or after other traumatic accidents, hospitalization and the provision of intravenous fluids is crucial to prevent shock and circulatory failure. Transfusion of donor blood can help to replace some of the lost erythrocytes.
If you have noticed symptoms of anemia in your dog, consult a veterinary clinic as soon as possible.