Abstract
Seven calves, seven goats and eight sheep were inoculated intraorally with 0.2 – 0.7 × 106 TCID50 of Border-Disease-Virus CH-BD4, isolated from a persistently infected sheep. After that they were examined for 70 days. Challenge exposure took place after an acclimatization period of 17 days. During that period, all animals were tested seronegative and pestiviruses were not detected. After infection five calves showed mild erosive lesions in the mucous mem-branes of the mouth. Six sheep and two goats showed alterations of different de-gree in the vulval circumference. Four sheep showed erosive lesions of the mouth. There were no significant changes either in the leukocyte nor in the lymphocyte concentration in any calf, goat or sheep. After challenge exposure, viral RNA was detected in the blood samples of three calves. In the calves group, a seroconversion could not be proven in any of the calves by ELISA. However, using the virus neutralization test one calf showed low titres of specific antibodies against BDV. Based on the repeated detection of viral RNA and the clear seroconversion we could conclude a successful infection in four goats and two sheep. All other goats and sheep remained seronegative