Equine amnionitis and fetal loss: mare abortion following experimental exposure to Processionary caterpillars (Ochrogaster lunifer).
Authors: Cawdell-Smith A J, Todhunter K H, Anderson S T, Perkins N R, Bryden W L
Journal: Equine veterinary journal
Summary
# Editorial Summary: Equine amnionitis and fetal loss Australian studs have recently documented a distinct abortion syndrome presenting in mid- to late-gestation mares, termed equine amnionitis and fetal loss (EAFL), which differs clinically from established pregnancy loss aetiologies. Cawdell-Smith and colleagues investigated the hypothesis that Processionary caterpillars (*Ochrogaster lunifer*) — insects present on affected properties — might be responsible for this condition by experimentally exposing pregnant mares to the caterpillars and monitoring outcomes. The researchers demonstrated that direct exposure to *O. lunifer* larvae triggered EAFL in exposed mares, establishing a causal link between the caterpillar's toxins and amnionitis leading to fetal loss during the vulnerable mid-to-late pregnancy window. For equine practitioners working in affected regions, this work highlights the importance of pasture management and caterpillar surveillance during critical breeding seasons, alongside recognition of EAFL as a distinct diagnostic entity requiring environmental rather than solely infectious intervention. Understanding this novel environmental hazard is particularly valuable for stud managers and veterinarians aiming to reduce unexplained abortion rates and implement targeted preventive strategies on at-risk properties.
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Practical Takeaways
- •Australian stud farm managers should monitor for Processionary caterpillars as a potential environmental risk factor for mid- to late-gestation abortions
- •Practitioners should recognize EAFL as a distinct syndrome with characteristic clinical presentation that differs from other known causes of mare abortion
- •Consider environmental and pasture management strategies to prevent caterpillar infestation on breeding farms in affected regions
Key Findings
- •Processionary caterpillars (Ochrogaster lunifer) were identified as a possible causal factor in unusual abortion cases in Australian mares
- •EAFL syndrome presents as clinically distinct abortions separate from other recognized pregnancy loss causes
- •Presence of Processionary caterpillars on affected stud farms was associated with abortion cases