Anemia is defined as a decrease in the number of red blood cells (red blood cells) circulating in the bloodstream. Red blood cells are made up of hemoglobin, an iron-rich protein that transports oxygen to tissues and organs. Depending on the extent of red blood cell consumption, the symptoms of anemia may be mild and life-threatening. Acute blood loss caused by trauma, immune-mediated cell destruction, renal failure, blood parasites and bone marrow disease are a small number of causes. The treatment plan is entirely dependent on the severity and mechanism of the anemia.
Red blood cells account for most of the cells found in the circulation. Red blood cell measurements are performed in several ways. First, the packed cell volume (PCV) is the percentage of whole blood composed of cells, with a normal value of about 35-55%, depending on the species and variety. Below this range is considered anemia and less than 12% is considered life-threatening. The absolute red blood cell count is the estimated number of cells per volume of whole blood. Normal dogs and cats contain more than 5 million cells per microliter (1 liter of 1 / 1,000,000th). Other tests that determine red blood cell health rather than quantity include MCV – mean red blood cell volume (cell size) and MCHC – mean red blood cell hemoglobin concentration (amount of hemoglobin bound to cells).
When anemia is found, it is classified as either regenerative or non-regenerating. Bone marrow should respond to anemia by producing more red blood cells; therefore, an increase in the number of immature cells called reticulocytes should be seen in laboratory results. If there are more than 60,000 reticulocytes per microliter, anemia is considered to be regenerative. Otherwise, anemia is called non-regeneration and should be the cause of myelosuppression. Non-regenerative anemia is usually more difficult to treat, and if it cannot be reversed it is gradual.
Treatment for acute blood loss may include blood transfusions. Intravenous whole blood or packaged red blood cells to correct anemia, giving the body time to regenerate its own cells.
A synthetic hormone called Epogen (erythropoietin) can be used to stimulate bone marrow to produce red blood cells. Erythropoietin is produced by the kidney; therefore, in chronic renal failure, Epogen can be supplemented to correct anemia. However, in response to Epogen injection to form antibodies, the effect of repeated injections is getting worse as kidney failure progresses.
In IMHA (immune-mediated hemolytic anemia), the body destroys its own red blood cells for some reason. Treatment with IMHA includes immunosuppressive drugs such as prednisone and azathioprine (Imuran). These drugs prevent the immune system from attacking red blood cells. It is almost always necessary to maintain a dose of steroids to prevent recurrence of anemia.
The prognosis of a pet diagnosed with anemia depends on the degree of anemia, whether the bone marrow is capable and actively producing new cells, and the underlying disease process that causes the initial blood loss. Regenerative anemia is generally easier to treat than non-regenerated forms. The prognosis of the pathogenic disease process will directly determine the outcome.