Experimental transmission with ovine rinderpest virus

Abstract The behaviour of ovine rinderpest virus in experimentally infected crossbred calves and indigenous sheep was studied in two phases. In the first phase, clinical manifestations were more pronounced in calves than in sheep. Leukopenia was significantly higher. However, there were no differences in duration of leukopenia between the two species. There was a positive correlation of leukopenia with fever in calves, which showed predominant lymphopenia. No mortality was noticed in sheep, whereas one calf died on Day 10 post-infection. In the second phase of the experiment, virus recovered from the reactor calf was subinoculated into another calf and sheep. The calf showed classical signs of rinderpest. In sheep, anorexia and diarrhoea were the only two signs noticed. Duration of leukopenia associated with reduced lymphocytes was 3 days in sheep whereas in calves for 8 days. Comparative responses of the two species suggest that calves may serve as a better indicator host than sheep in in vivo characterization of rinderpest isolates of ovine origin.