Haematological parameters and altered erythrocyte metabolism in anaemic dogs

In previous studies, an increase in the activity of pyruvate kinase (PK) and glucose-6-phosphate dehydrogenase (G6PDH), an increase in the concentration of 2,3-diphosphoglycerate (2,3DPG), and alterations in osmotic fragility were found in dogs with haemolytic anaemia. These changes were mainly caused by the presence of immature red cells found in regenerative anaemias. In the present study, the same parameters were evaluated in dogs with different types of anaemia. The haematological patterns of 40 anaemic dogs were analysed to define the pathogenesis and the haematological features of each case. Non-regenerative anaemias could be attributed principally to chronic diseases and to the haemolysis that accompanies the early stages of canine babesiosis. Regenerative anaemias were mainly due to haemolysis, in some cases with an immune-mediated pathogenesis. PK activity was higher in regenerative than in non-regenerative anaemias, but G6PDH activity and 2,3DPG concentration increased in both types of anaemia. This suggests that PK activity is influenced by the presence of immature red cells, but the requirements for reducing compounds and oxygen are not dependent on the type of anaemia. Abnormalities in osmotic fragility were detected in haemolytic anaemias and in those non-regenerative anaemias in which reticulocyte percentage, but not reticulocyte production index (RPI), increased. The osmotic fragility could be used as an early indicator of erythrocyte regeneration.