Hematological manifestations in dogs progressing to the iron deficiency anemia by repeated phlebotomy

Progressing to the iron deficiency anemia was experimentally induced in 4 clinically healthy dogs by repeated phlebotomy to characterize hematologic features, serum iron values, and RBC indices. Abnormal RBC morphologies were also evaluated semiquantitatively on Wright's-stained blood films. Hematologic abnormalities in early stage of anemia included decreased both hematocrit and hemoglobin, and reticulocytosis, with no changes in mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC) were represented. In intermediate stage, decreased serum iron concentration with microcytosis and hypochromia were prominent. In late stage, red cell distribution width and Mentzer's index were out of reference ranges in the majority of dogs. In this study microcytic anemia was appeared at the hemoglobin range of 5.1-7.2 g/dl. On most sampling days, platelet counts and white blood cells were within the reference ranges, with some minor variations. Iron deficiency was not necessarily associated with microcytic anemia. Judging from the sequential changes of both MCV and MCHC, 3 patterns of anemia were sequentially observed: initially normocytic normochromic, intermediate normocytic hypochromic or normocytic normochormic, and finally microcytic hypochromic. The most frequent morphologic abnormalities were target cells. Occasional elliptocyte, acanthocyte, stomatocyte, kinzocyte, dacrocyte and schistocyte were also noted on the blood films.