Sheep Abortion: Causes, Infection Risks & What to Do Next

Sheep abortion has many possible causes, but infectious disease is one of the biggest concerns. Merck notes that normal fetal loss after pregnancy diagnosis is usually low, and Cornell advises expecting an infectious cause when more than 2% of the flock aborts. In practical terms, one abortion may be an isolated event, but repeated losses or a late-gestation cluster should be treated as a flock health problem until proven otherwise.

Common infectious causes include enzootic abortion of ewes from Chlamydia abortus, campylobacteriosis, toxoplasmosis, listeriosis, Q fever from Coxiella burnetii, and border disease. These conditions can cause late-term abortion, stillbirths, or weak lambs. Some are more likely to spread around lambing because the placenta and birth fluids carry large numbers of organisms.

Noninfectious causes also matter. Poor nutrition, severe stress, toxic exposures, fever, and some environmental problems can contribute to pregnancy loss. Your vet may also consider less common regional causes, including viral diseases or congenital problems, depending on where your flock lives and what exposures are possible.

Several abortion causes in sheep can also affect people. Cornell and Merck both highlight zoonotic risk from organisms linked to abortion materials, and pregnant women are a special concern because some infections can cause serious pregnancy complications. That is why safe handling and fast veterinary guidance are so important.

See your vet immediately if a ewe aborts, delivers a weak premature lamb, seems depressed, has a fever, stops eating, strains without passing the placenta, or if more than one ewe is affected. This is especially urgent when abortions happen in the last few weeks of pregnancy, when there is a foul-smelling discharge, or when the ewe appears neurologic or severely ill. Fast action helps protect both the ewe and the rest of the flock.

You should also contact your vet right away if anyone in the household is pregnant, immunocompromised, or had direct contact with the placenta or fluids. Organisms such as Chlamydia abortus, Coxiella burnetii, Listeria monocytogenes, and Toxoplasma gondii can pose human health risks. Until your vet advises otherwise, keep the ewe isolated and limit traffic through the lambing area.

Monitoring at home is only appropriate after your vet has been contacted and the ewe is stable. A bright ewe that is eating, drinking, and not straining may be managed on-farm while diagnostics are arranged, but abortion should still not be treated as routine. Even when the ewe looks well, the flock may still be at risk.

If you can do so safely, save the fetus and placenta for testing. Refrigerate them if possible, but do not freeze unless your vet or diagnostic lab tells you to. Wear gloves, bag materials carefully, and wash hands and equipment thoroughly afterward.

Your vet will start with the ewe and the flock history. They will ask how far along the pregnancy was, whether other ewes have aborted, whether new animals were introduced, what vaccines and feed changes occurred, and whether cats, wildlife, or spoiled silage may have been involved. They will also check the ewe for fever, dehydration, retained placenta, metritis, mastitis, or signs of systemic illness.

Diagnostics often focus on the fetus, placenta, and dam. Cornell recommends submitting placenta, fetal tissues, and blood from the ewe for abortion workups. Depending on the case, your vet may collect fresh and formalin-fixed tissues, vaginal samples, and paired blood samples. Placenta is especially valuable, so it should be saved whenever possible.

Treatment depends on the likely cause and the ewe's condition. Your vet may recommend isolation, anti-inflammatory care, fluids, uterine monitoring, or antibiotics in selected flock situations where they are appropriate under veterinary oversight. They may also advise flock-level steps such as separating pregnant groups, improving sanitation, reviewing feed storage, and discussing vaccination or strategic medication plans for exposed ewes.

Just as important, your vet will help with biosecurity and human safety. That may include instructions for handling bedding, placentas, and dead lambs; limiting exposure for pregnant people; and deciding whether the event looks isolated or part of an outbreak that needs broader testing.

After you have contacted your vet, move the ewe to a clean, separate pen away from pregnant flockmates. Keep her warm, dry, and quiet, and make sure she has easy access to fresh water and good-quality feed. Watch for appetite, attitude, rectal temperature if your vet recommends it, vaginal discharge, straining, and whether the placenta passes normally.

Handle all abortion materials as potentially infectious. Wear disposable gloves, dedicated boots, and washable outerwear. Bag the fetus and placenta for your vet or diagnostic lab if instructed, and clean the area thoroughly after removal. Cornell recommends complete disposal of materials associated with aborted and normal births, including placentas and dead lambs, because some organisms spread heavily in these tissues.

Protect people as well as sheep. Pregnant people should not handle aborting ewes, placentas, or contaminated bedding. Anyone cleaning the area should wash hands well and avoid touching their face while working. If a person develops flu-like illness after exposure, they should contact a physician and mention contact with sheep abortion materials.

Do not start leftover antibiotics or flock medications on your own. Some outbreaks do call for flock-level treatment or prevention, but the right plan depends on the cause, timing of pregnancy, and your operation's goals. Your vet can help you choose a conservative, standard, or advanced path that fits both the medical situation and your cost range.