Kinetics of experimental Salmonella abortus ovis infection in ewes.

The multiplication and dissemination of Salmonella abortus ovis, a Salmonella serotype which is specific for small ruminants, were studied in 17 culled non pregnant ewes. The virulent strain 15/5, that has previously been used either for the development of mouse models or as an abortion inducing agent in sheep, was injected by the subcutaneous route at a sublethal dose of 10(9) salmonella per animal. In most animals, it induced only transient hyperthermia and pronounced local reactions. Groups of four to five ewes were killed on days 3, 6, 10, and 14 for bacterial counts of their lymph nodes and organs. Maximal level of infection was on day 6, at which time the lymph node draining the site of inoculation (right prescapular lymph node), spleen, liver and lungs were regularly infected. On day fourteen, S abortus ovis were regularly reisolated only from right prescapular lymph nodes and local reactions.