Tactical control of ovine Campylobacter abortion outbreaks with a bacterin

Abortions due to Campylobacter fetus fetus (C. fetus fetus) were diagnosed in three Canterbury ewe flocks 6 weeks prior to lambing. In two of the flocks, two inoculations of a C. fetus fetus bacterin, 10 days apart, reduced the incidence of abortions in the treated ewes to about one third and one half respectively of the level in the control ewes in the same flock. The treatment had no effect in a third flock where an outbreak had been in progress for 2 weeks before investigations started. The results confirm earlier Scottish work where pregnant sheep were inoculated with a C. fetus fetus vaccine following artificial challenge with C. fetus fetus. This inoculation significantly reduced the number of C. fetus fetus abortions. The results also indicate that treatment must start very early in an outbreak.