Babesia ovis isolated from field animals were used to infect the spleenectomised and susceptible lambs. Blood samples were collected from. lambs during the rise parasitemia. Seven lambs were inoculated intravenosly with 540 infected erythrocytes. Clinical and parasitological observations were studied until 21 days after infection. The first sign of disease was rise of tempreture which observed on third & fifth days post inoculation. This was followed by restlessness, marked in appetite and the temperature rised up to 42°C until third and forth days, rapid heart beat, increase respiratory rate, anemia and icterus were present. Affected animals became thin and emaciated the haemoglobinuria had not been observed and finally infected animals getting well little by little. Spleenectomised animals showed severe haemoglobinuria and death occured on fifth and eighth days after inoculation.
)