Abstract
Two male calves were inoculated subcutaneously with 10ml of blood infected with small-sized piroplasma and examined for clinical and hematological changes for 129 days after inoculation. As a result, there was an almost parallel relationship between the severity of anemia and the number of parasitizing protozoa, both of which reached a maximum level 50-70 days after infection. The anemia was accompanied by hyperchromic macrocythemia. The bone marrow began to show an enhanced function of producing cells of the erythrocytic series in the early stage of anemia. The enhanced function persisted in the convalescent stage after the erythrocyte count returned to normal. The ratio of myeloid to erylthroid cells reflected these changes well. Erythrocytes were reduced in resistance and serum lipoid phosphorus decreased in amount. These changes seemed to be related to the mechanism of hemolysis. A marked increase in serum gamma globulin was observed in the recovery stage of infection.
