Disease incidence of dogs babesiosis reached 42% concerning other pathologies in 2003, for comparison in 2002 - 21%. Area of tick-transmitterliving has extended. The connection between the form both size of the parasite and severity of disease is revealed. Phagocytosis rate parameters were determined in blood of dog suffering from babesiosis. It has been established, that phagocytyc activity are depended on severity of disease. Both phagocytyc index and phagocytyc number at mild uncomplicated and severe uncomplicated babesiosis were increased, when as at complicated babesiosis these parameters were lower, than at healthy animals. There were anaemia (decrease of quantity of erythrocytes and haemoglobin), leucocytosis (eosinophilia, shift of nucleus to the left with increase young and polymorphonuclear neutrophiles, monocytosis) in peripherial blood.