ROUTINE HAEMATOLOGY RED BLOOD CELL INDICES RBC indices are helpful in the classification of certain anemias MCV(n飞升)=PCV(LL)×1000 total red cells(×1012/L) MCH(pg皮克)= total haemoglobin(g/d)×10/ total red blood cls(×1012/L) MCHC(g/dl= total haemoglobin(g/dI/PCV(L/L)
RED BLOOD CELL INDICES MCV(fl飞升)= PCV (L/L) × 1000/ total red cells (× 1012/L) MCH (pg皮克) = total haemoglobin (g/dl) × 10/ total red blood cells (× 1012/L) MCHC (g/dl) = total haemoglobin (g/dl)/PCV (L/L) RBC indices are helpful in the classification of certain anemias. ROUTINE HAEMATOLOGY
ROUTINE HAEMATOLOGY Differential white cell counts / The differential white cell count is performed by counting 200 leucocytes in a blood smear. The cells are counted along the long edge of the smear, using the battlement meander method: four high-power fields are counted in one direction, then four more in a direction at right angles to the first, and so on, following the shape of a battlement The percentage of each type of cell is determined. This percentage is then multiplied by the total white cell count to obtain an absolute count for each cell type
Differential white cell counts The differential white cell count is performed by counting 200 leucocytes in a blood smear. The cells are counted along the long edge of the smear, using the battlement meander method: four high-power fields are counted in one direction, then four more in a direction at right angles to the first, and so on, following the shape of a battlement. The percentage of each type of cell is determined. This percentage is then multiplied by the total white cell count to obtain an absolute count for each cell type. ROUTINE HAEMATOLOGY
ROUTINE HAEMATOLOGY Plasma protein concentration (Reference range: 60-80 g/l for the dog and cat) / Total plasma protein(TPP)and PCV should be interpreted together Qualitative examination of a blood smear a blood smear should always be evaluated when automated cell counts are made or when in-practice instrumentation is limited to a centrifuge for PCv Preparation of a blood smear A small drop of blood is placed on one end of a glass slide, using a capillary tube. A spreader slide(made by breaking off the comer of another slide, after scoring it with a glass cutter or diamond writer) is placed on to the slide holding the blood drop, in front of the drop and at an angle of 20 40
Plasma protein concentration (Reference range: 60-80 g/1 for the dog and cat) Total plasma protein (TPP) and PCV should be interpreted together. Qualitative examination of a blood smear A blood smear should always be evaluated when automated cell counts are made or when in-practice instrumentation is limited to a centrifuge for PCV Preparation of a blood smear A small drop of blood is placed on one end of a glass slide, using a capillary tube. A spreader slide (made by breaking off the comer of another slide, after scoring it with a glass cutter or diamond writer) is placed on to the slide holding the blood drop, in front of the drop and at an angle of 20- 40°. ROUTINE HAEMATOLOGY
ROUTINE HAEMATOLOGY ANAEMIA Anaemia is characterized by an absolute decrease in red cell count haemoglobin concentration and Pcv Acute haemorrhage Acute haemorrhage may be due to trauma or surgery, bleeding gastrointestinalulcers or tumours, rupture of a vasculartumour(e.g. splenic hemangiosarcoma), or a coagulopathy(e.g. warfarin toxicity). Immediately following acute haemorrhage the red cell parameters including PCV, are normal because both red cells and plasma have been lostin proportion. Compensatory mechanisms such as splenic contraction may further offset any fall in PCV. The PCv falls when blood volume is replaced by interstitial fluid and so does not indicate the full magnitude of blood loss for at least 24 hours after the onset of haemorrhage
ANAEMIA Anaemia is characterized by an absolute decrease in red cell count, haemoglobin concentration and PCV. Acute haemorrhage Acute haemorrhage may be due to trauma or surgery, bleeding gastrointestinal ulcers or tumours, rupture of a vascular tumour (e.g. splenic haemangiosarcoma), or a coagulopathy (e.g. warfarin toxicity). Immediately following acute haemorrhage the red cell parameters, including PCV, are normal because both red cells and plasma have been lost in proportion. Compensatory mechanisms such as splenic contraction may further offset any fall in PCV. The PCV falls when blood volume is replaced by interstitial fluid and so does not indicate the full magnitude of blood loss for at least 24 hours after the onset of haemorrhage. ROUTINE HAEMATOLOGY
ROUTINE HAEMATOLOGY Chronic haemorrhage Chronic external blood loss(e.g. chronic gastrointestinal haemorrhage, renalor bladder neoplasia) initially results in a regenerative anaemia but gradually the anaemia becomes non-regenerative as the iron stores become depleted. Young animals become iron-deficient more bone marrow is already very active producing red cells quickly than adults following blood loss, partly because they have low iron stores and partly because their to match their growth rate and so has less capacity to increase its rate of haemopoiesis Haemolytic anaemias Most cases of haemolytic anaemia are immune-mediated. In the dog most cases of immune-mediated is haemolytic anaemia(IHA)are primary (idiopathic)and are termed autoimmune haemolytic anaemia(AIHa). THA may occur in association with: drugs(e.g potentiated sulphonamides); lymphoreticular diseases(e.g lymphoid leukaemia); systemic lupus erythematosus; or infections(e.g Babesia, bacterial endocarditis)
Chronic haemorrhage Chronic external blood loss (e.g. chronic gastrointestinal haemorrhage, renal or bladder neoplasia) initially results in a regenerative anaemia but gradually the anaemia becomes non-regenerative as the iron stores become depleted. Young animals become iron-deficient more bone marrow is already very active producing red cells quickly than adults following blood loss, partly because they have low iron stores and partly because their to match their growth rate and so has less capacity to increase its rate of haemopoiesis. Haemolytic anaemias Most cases of haemolytic anaemia are immune-mediated. In the dog most cases of immune-mediated is haemolytic anaemia (IHA) are primary (idiopathic) and are termed autoimmune haemolytic anaemia (AIHA). IHA may occur in association with: drugs(e.g. potentiated sulphonamides); lymphoreticular diseases (e.g. lymphoid leukaemia); systemic lupus erythematosus; or infections (e.g. Babesia, bacterial endocarditis). ROUTINE HAEMATOLOGY