An animal becomes anemic when it has an insufficient number of red blood cells carrying oxygen to its body. Without oxygen, the cells of the body become damaged and may die. The hearts of anemic animals beat faster, pumping the blood at an increased rate, in an attempt to direct more oxygen to the cells. Because animals with anemia have fewer red blood cells, their blood is thinner. As a result, anemic animals can develop heart murmurs; the noise a heart murmur makes comes from the turbulent sound thinner blood makes as it flows through the heart.
The clinical signs of the disease depend on the severity of the anemia and how quickly the anemia occurred. Those animals that become anemic gradually have a much greater chance of recovery than animals whose anemia is more sudden. With gradual anemia, the body has the time to adjust to the decreased red blood cell count; animals that become anemic very quickly, however, may die because their bodies cannot handle the sudden loss in red blood cells and oxygen.
The many possible causes of anemia can be divided into three categories. Blood loss anemia is caused by the leaking of blood out of the vascular system. Hemolytic anemia is the result of the destruction of red blood cells circulating within the blood stream. Nonregenerative anemia refers to a decrease in erythrocyte production.
