A failure to produce red blood cells in the bone marrow. Regeneration is measured by the number of reticulocytes in circulation. Any dog with anemia (PCV less than 37%) that has less than 60,000 reticulocytes is considered non-regenerative. The greater degree of anemia, the larger the number of reticulocytes is required to be considered regenerative.
Failure of bone marrow stem cells to produce RBC (erythroid) cells occurs in the following conditions:
- Pure red cell aplasia: A diagnosis of PRCA is made by examining bone marrow aspirates (or core biopsy) for evidence of RBC (erythroid) hypoplasia and a reduction in the erythroid: myeloid ratio of the marrow stem cells. The ratio between myeloid series and erythroid cells is relevant to bone marrow function, and also to diseases of the bone marrow and peripheral blood, such as leukemia and anemia. The normal myeloid-to-erythroid ratio is around 3:1; this ratio may increase in myelogenous leukemias, decrease in polycythemias, and reverse in cases of thalassemia. A myelocyte is a young cell of the granulocytic series, occurring normally in bone marrow, but not in circulating blood
- Aplastic anemia
- Bone marrow suppression
Failure of erythrocyte maturation can occur with:
- Iron deficiency
- Vitamin B12/folate deficiency
Erythrocytes are produced from stem cells in the bone marrow and they then undergo sequential stages of maturation before and after they are released into the circulation.
The red blood cells are usually normochromic, Mean Corpuscular Hemoglobin Concentration (MCHC), and normocytic, Mean Corpuscular Volume (MCV), but poikilocytosis may be apparent in cases of maturation defect anemia.