Chlamydial and campylobacter abortion cause significant reproductive losses and welfare impact in sheep, with vaccination programs providing effective prevention.
Infectious abortion causes acute welfare impact for ewes who deliver dead or dying lambs after near-full-term pregnancy. Ewes that abort show distress and strong maternal behavior directed toward dead or unresponsive lambs. Vaccination programs prevent this acute distress and the chronic reproductive failure that reduces flock productivity. Biosecurity to prevent introduction of infection is more cost-effective and welfare-positive than managing endemic disease.