Which two pathogens are among the most common causes of abortion in sheep?

Which two pathogens are among the most common causes of abortion in sheep?

• A. Campylobacter fetus (Vibriosis) & Chlamydia psittaci (enzootic abortion of ewes)
• B. Listeria monocytogenes & Brucella ovis
• C. Escherichia coli & Salmonella Typhimurium
• D. Toxoplasma gondii & Neospora caninum

Answer: (A)

Abortion in sheep is often driven by contagious, flock-spreading infectious agents that cause late-gestation losses. The two pathogens most commonly implicated in this pattern are Campylobacter fetus (vibriosis) and Chlamydia psittaci (enzootic abortion of ewes). Campylobacter fetus is transmitted mainly via the fecal-oral route and can persist in the environment, leading to abortion storms in late pregnancy and shedding infectious material that spreads quickly through the flock. Control hinges on vaccination of ewes before mating where available, strict hygiene, prompt removal and proper disposal of aborted material, and isolating affected animals to limit transmission. Chlamydia psittaci is highly contagious and shed in placental tissue, vaginal discharges, and aborted fetuses; it also tends to cause abortions in late gestation and can trigger outbreaks in naive flocks. Vaccination and good biosecurity are key to prevention, and there is a notable zoonotic risk for people handling placentas or abortive material. While other pathogens such as Listeria, Toxoplasma, Neospora, Brucella, or certain enteric bacteria can cause abortions, the combination of these two agents is a well-recognized, frequent cause of ovine abortion across many settings, which is why they are identified as the common culprits in this context.

Abortion in sheep is often driven by contagious, flock-spreading infectious agents that cause late-gestation losses. The two pathogens most commonly implicated in this pattern are Campylobacter fetus (vibriosis) and Chlamydia psittaci (enzootic abortion of ewes). Campylobacter fetus is transmitted mainly via the fecal-oral route and can persist in the environment, leading to abortion storms in late pregnancy and shedding infectious material that spreads quickly through the flock. Control hinges on vaccination of ewes before mating where available, strict hygiene, prompt removal and proper disposal of aborted material, and isolating affected animals to limit transmission. Chlamydia psittaci is highly contagious and shed in placental tissue, vaginal discharges, and aborted fetuses; it also tends to cause abortions in late gestation and can trigger outbreaks in naive flocks. Vaccination and good biosecurity are key to prevention, and there is a notable zoonotic risk for people handling placentas or abortive material. While other pathogens such as Listeria, Toxoplasma, Neospora, Brucella, or certain enteric bacteria can cause abortions, the combination of these two agents is a well-recognized, frequent cause of ovine abortion across many settings, which is why they are identified as the common culprits in this context.