POLYCYTHEMIA

摘要

Polycythemia is a disease that has been associated with an increase of erythrocytes in the circulation system. In actuality, polycythemia means an increase in numbers of all the circulating cells. The correct terminology is erythrocytosis. Clinically,this is demonstrated by an increase in the packed cell volume (PCV), hematocrit (HCT), hemoglobin concentration or red blood cell (RJ3C) count. If the only increase hematologically is the RBC parameters, then erythrocytosis is a more appropriate label.Dogs that live at high altitudes and certain dog breeds that naturally have HCTs above the normal reference ranges. Greyhounds for example can have hematocrits (HCT) of 70%. If there is an increase in all cell lines, it is more appropriate to label this is as polycythemia.Erythrocytosis can be further classified as relative or absolute. Relative erythrocytosis is typically due to the redistribution of RBCs in circulation or an intracompartmental fluid shift. It may be due to the hemoconcentration seen with dehydration. With relative erythrocytosis, the PCV and the total serum protein concentration is also increased. In dogs with hemorrhagic gastroenteritis, there may be a normal total serum protein with an increased PCV. After rehydration with fluid therapy, one wouldexpect the PCV to begin to normalize.