Aspergillosis Abortion in Sheep: Fungal Pregnancy Loss Explained

Quick Answer
  • Aspergillosis abortion is a fungal cause of pregnancy loss in ewes, usually occurring in late gestation after Aspergillus reaches the placenta through the bloodstream.
  • Many ewes look normal until they abort, but you may notice premature labor, stillborn or weak lambs, retained fetal membranes, or abnormal thickened placenta.
  • Diagnosis usually depends on submitting the fetus and especially the placenta for fungal culture and histopathology, because finding Aspergillus in the environment alone does not confirm disease.
  • Treatment focuses on the ewe's recovery, flock biosecurity, and reducing mold exposure rather than trying to treat the fetus after abortion has started.
  • Prompt cleanup, isolation of aborting ewes, and reviewing feed and bedding quality with your vet can help limit additional losses.
Estimated cost: $150–$900

What Is Aspergillosis Abortion in Sheep?

Aspergillosis abortion in sheep is a mycotic, or fungal, abortion caused most often by Aspergillus species. These fungi are common in the environment, especially in moldy hay, bedding, feed, and dusty organic material. In affected ewes, the fungus usually spreads through the bloodstream to the uterus and placenta, where it causes placentitis and pregnancy loss.

This problem is usually seen as a sporadic late-term abortion rather than a classic abortion storm. A ewe may appear healthy until she aborts, delivers weak lambs, or passes an abnormal placenta. The placenta often has some of the most important lesions, including thickening between cotyledons and necrosis of placental tissue.

Because Aspergillus is widespread in barns and on farms, diagnosis is not based on exposure alone. Your vet usually needs placental or fetal tissue testing to show that the fungus actually invaded tissue and caused disease. That distinction matters, because many other infectious and noninfectious causes of abortion in sheep can look similar at first.

Symptoms of Aspergillosis Abortion in Sheep

  • Late-gestation abortion
  • Stillborn lambs or weak lambs at birth
  • Retained fetal membranes after abortion or lambing
  • Abnormal placenta with thickened, leathery, or necrotic areas
  • Premature labor or unexpected early lambing
  • Minimal illness in the ewe before abortion
  • Occasional fever, depression, or reduced appetite
  • Ringworm-like skin lesions on the fetus in some mycotic abortions

Call your vet promptly for any abortion in a ewe, especially if it happens in the last few weeks of pregnancy or if more than one ewe is affected. Even when the ewe seems bright and eating, the fetus and placenta should be saved for testing if possible. Placental tissue is often the most useful sample.

See your vet immediately if the ewe is weak, has a foul-smelling discharge, keeps straining, has not passed the placenta within the expected time, or if multiple abortions occur in the flock. Several infectious abortion causes in sheep can spread within a flock, and some are also important for human health.

What Causes Aspergillosis Abortion in Sheep?

Aspergillus species are ubiquitous environmental fungi. Sheep are exposed through inhalation or contact with mold-contaminated organic material, including poor-quality hay, spoiled feed, damp bedding, and dusty housing. In mycotic abortion, the organism typically reaches the uterus through the bloodstream rather than by direct spread from the outside.

Once the fungus localizes in the placenta, it can cause placentitis, cotyledon damage, and reduced oxygen and nutrient delivery to the fetus. That placental injury is what leads to fetal death, weak lambs, or abortion. In ruminants, placental lesions may be more obvious than fetal lesions.

Risk tends to rise when ewes are housed in damp, poorly ventilated conditions or when feed storage allows mold growth. Not every ewe exposed to mold will abort, and not every abortion linked to mold is caused by Aspergillus. That is why your vet will also consider other common sheep abortion causes such as chlamydial abortion, toxoplasmosis, campylobacteriosis, listeriosis, salmonellosis, and Q fever.

How Is Aspergillosis Abortion in Sheep Diagnosed?

Diagnosis starts with a flock history and physical exam, including how far along the ewe was, whether other abortions have occurred, and whether there has been exposure to moldy feed or bedding. Your vet may examine the ewe, fetus, and placenta and ask that all aborted materials be handled carefully and kept cool for testing.

The most useful diagnostic approach is usually laboratory evaluation of the placenta and fetal tissues. This may include fungal culture, histopathology, and direct microscopic examination. In ruminant mycotic abortion, seeing fungal hyphae invading placental or fetal tissue is especially important, because growing Aspergillus from the environment alone does not prove it caused the abortion.

Your vet may also recommend testing for other infectious abortion agents at the same time, since mixed infections and look-alike diseases can occur. If more than one ewe aborts, a broader flock investigation may be needed, including feed review, housing assessment, and biosecurity planning.

Treatment Options for Aspergillosis Abortion in Sheep

Spectrum of Care means you have options. Here are treatment tiers at different price points.

Budget-Conscious Care

$75–$250
Best for: Single abortion in an otherwise stable ewe when the flock has low recent abortion pressure and the pet parent or producer needs a practical first step.
  • Isolation of the ewe from pregnant flockmates
  • Basic farm exam or teleconsult guidance with your vet where appropriate
  • Removal and careful disposal of aborted materials
  • Monitoring for fever, poor appetite, discharge, or retained placenta
  • Review of hay, feed, and bedding for visible mold contamination
Expected outcome: The ewe often recovers well with monitoring if no uterine infection or retained membranes develop, but the exact cause may remain unconfirmed without lab testing.
Consider: Lower upfront cost range, but less diagnostic certainty. This can make it harder to protect the rest of the flock if another infectious cause is involved.
Most Common

Recommended Standard Treatment

$150–$500
Best for: Most cases, especially late-term abortion, abnormal placenta, weak lambs, or any situation where protecting the rest of the flock matters.
  • Farm call or clinic exam by your vet
  • Submission of placenta and fetal tissues for diagnostic testing
  • Supportive care for the ewe as needed, such as anti-inflammatory treatment, fluids, or uterine monitoring under veterinary direction
  • Assessment for retained fetal membranes or metritis
  • Flock-level biosecurity advice, including isolation and sanitation steps
  • Targeted review of feed storage, bedding, and ventilation
Expected outcome: Good for the ewe if complications are addressed early. Flock outlook improves when the cause is confirmed and environmental mold exposure is reduced quickly.
Consider: Higher cost range than observation alone, but it gives better answers and more useful prevention planning. It still may not prevent loss of the current pregnancy.

Advanced / Critical Care

$500–$900
Best for: Multiple abortions, valuable breeding animals, very sick ewes, or cases where a flock outbreak could cause major production losses.
  • Urgent farm visit or referral-level reproductive workup
  • Ultrasound or additional diagnostics for sick ewes or ongoing flock losses
  • Expanded lab panel to rule out multiple abortion agents
  • Treatment of complications such as severe metritis, dehydration, toxemia, or prolonged retained membranes under veterinary supervision
  • Detailed flock investigation with housing, nutrition, and environmental risk assessment
Expected outcome: Variable for the pregnancy, but often favorable for the ewe when complications are treated promptly. Flock-level prognosis improves when the source is identified and corrected.
Consider: Most intensive and highest cost range. It offers the most information and support, but may exceed what is needed for a single uncomplicated case.

Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.

Questions to Ask Your Vet About Aspergillosis Abortion in Sheep

Bring these questions to your vet appointment to get the most out of your visit.

  1. Which samples should I save right now, and how should I store the fetus and placenta before transport?
  2. Does this look more like a sporadic fungal abortion or something that could spread through the flock?
  3. Should we test for other abortion causes at the same time, such as chlamydial abortion, toxoplasmosis, campylobacteriosis, or Q fever?
  4. Does this ewe need treatment for retained fetal membranes, uterine infection, pain, or dehydration?
  5. How long should I isolate this ewe, and what cleaning steps matter most after an abortion?
  6. Could moldy hay, spoiled feed, or damp bedding be contributing, and what changes do you recommend?
  7. If more ewes abort, at what point should we consider this a flock-level emergency?
  8. Are there human health precautions my family or farm staff should follow when handling aborted materials?

How to Prevent Aspergillosis Abortion in Sheep

Prevention centers on reducing mold exposure and responding quickly to every abortion. Store hay and feed in dry, well-ventilated areas, discard visibly moldy or musty material, and keep bedding as clean and dry as possible. Good ventilation matters, especially in winter housing where moisture and organic dust can build up.

If a ewe aborts, isolate her promptly and remove aborted tissues and contaminated bedding right away. Wear gloves and use careful hygiene when handling placentas, fetuses, and uterine discharge. Even if Aspergillus is suspected, other infectious abortion causes may be present, and some can affect people.

Work with your vet on a flock abortion plan before lambing season starts. That may include deciding which lab to use, how to package samples, when to call after a single abortion, and how to review feed quality and housing risks. Fast diagnostics and practical management changes often do more to protect the flock than waiting to see if another ewe aborts.

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