Eastern tent caterpillars (Malacosoma americanum) cause mare reproductive loss syndrome.
Abstract: A new equine abortigenic disease, mare reproductive loss syndrome (MRLS), was recognized and significantly impacted the Ohio Valley in the springs of 2001 and 2002. MRLS caused approximately 330 million US dollars in losses in 2001. An epidemiological investigation of MRLS associated occurrence of the disease with exposure to eastern tent caterpillars (M. americanum). This work investigates the epidemiological association between M. americanum and MRLS to determine if this association was correlative or causative. A pilot study and simulated exposure to M. americanum and their excreta on pasture grasses. The pilot study advanced exposure of pregnant mares to M. americanum materials and 18 of the 29 mares in the study aborted with symptoms of MRLS before other cases were reported in the region. In, three of seven mares exposed to M. americanum aborted, while mares in control (n=6) and M. americanum frass (n=7) treatments had no losses. In, mares were fed frozen insect larvae in feed buckets mixed with oats. Abortions occurred in three of five mares receiving frozen M. americanum, while mares that were fed autoclaved M. americanum (n=5) or frozen gypsy moth larvae (n=4) had no abortions due to MRLS. In, M. americanum larvae were dissected and fractionated. Statistically significant numbers of abortions occurred only in the positive control group and in association with the M. americanum exoskeleton. All abortions induced by exposure to M. americanum exhibited changes in echogenicity of fetal fluids and bacteriological findings post abortion that were consistent with MRLS. These studies support the hypothesis that ingestion of M. americanum larvae induces the MRLS-type equine abortions, and provide experimental evidence that this lepidopteran larva can cause an abortigenic disease in a vertebrate host.
Publication Date: 2004-03-17 PubMed ID: 15019520DOI: 10.1016/j.jinsphys.2003.11.008Google Scholar: Lookup
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- Clinical Trial
- Controlled Clinical Trial
- Journal Article
- Research Support
- U.S. Gov't
- Non-P.H.S.
Summary
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The research article analyzes the connection between Eastern tent caterpillars (Malacosoma americanum) and mare reproductive loss syndrome (MRLS), a disease causing equine abortions. The study provides evidence that ingestion of M. americanum by pregnant mares can instigate MRLS-related abortions.
Understanding Mare Reproductive Loss Syndrome (MRLS)
- The paper focuses on MRLS, a disease that had caused substantial losses in the equine industry in the Ohio Valley, particularly in 2001 and 2002.
- Notably, $330 million was lost in 2001 due to this abortive condition in mares.
- An epidemiological study linked the incidence of MRLS to contact with Eastern tent caterpillars (M. americanum).
Investigating the Association of Eastern tent caterpillars (M. americanum) and MRLS
- The researchers carried out an in-depth study to check if the association of M. americanum and MRLS was merely correlative or definitely causative.
- The researchers conducted exposure tests on pregnant mares with M. americanum and noted the outcomes. They observed that 18 of the 29 mares in the study aborted with MRLS symptoms even before regional reports of MRLS surfaced.
- In another experiment, mares were made to ingest frozen M. americanum larvae, and three out of the five mares aborted. No abortions were recorded amongst mares fed autoclaved M. americanum or frozen gypsy moth larvae.
Results and Conclusion
- The scientists dissected and analyzed M. americanum larvae and found a significant number of abortions only in the group exposed to M. americanum exoskeleton.
- Mares that aborted after exposure to M. americanum showed changes in fetal fluid echogenicity and bacteriological findings after abortion consistent with MRLS.
- The collective results of these studies supported the authors’ hypothesis that ingestion of M. americanum larvae instigates MRLS-associated equine abortions. They concluded that the eastern tent caterpillar is capable of causing a disease that triggers abortions in a vertebrate host.
Cite This Article
APA
Webb BA, Barney WE, Dahlman DL, DeBorde SN, Weer C, Williams NM, Donahue JM, McDowell KJ.
(2004).
Eastern tent caterpillars (Malacosoma americanum) cause mare reproductive loss syndrome.
J Insect Physiol, 50(2-3), 185-193.
https://doi.org/10.1016/j.jinsphys.2003.11.008 Publication
Researcher Affiliations
- Department of Entomology, University of Kentucky, Lexington, KY 40546, USA.
MeSH Terms
- Abortion, Veterinary / etiology
- Animal Feed / adverse effects
- Animals
- Estrogens / blood
- Female
- Fetal Death / etiology
- Food Contamination
- Horses / physiology
- Larva / pathogenicity
- Moths / pathogenicity
- Ohio
- Pilot Projects
- Pregnancy
- Pregnancy Outcome / veterinary
- Pregnancy, Animal / blood
- Progesterone / blood
Citations
This article has been cited 7 times.- Lea KM, Smith SR. Using On-Farm Monitoring of Ergovaline and Tall Fescue Composition for Horse Pasture Management.. Toxins (Basel) 2021 Sep 25;13(10).
- Berman TS, Inbar M. Revealing cryptic interactions between large mammalian herbivores and plant-dwelling arthropods via DNA metabarcoding.. Ecology 2022 Jan;103(1):e03548.
- Chapuis RJJ, Ragno VM, Ariza CA, Movasseghi AR, Sayi S, Uehlinger FD, Montgomery JB. Septic fibrinous pericarditis in 4 horses in Saskatchewan following an outbreak of forest tent caterpillars in 2017.. Can Vet J 2020 Jul;61(7):724-730.
- Berman TS, Messeri N, Glasser TA, Inbar M. Innate ability of goats to sense and avoid ingestion of noxious insects while feeding.. R Soc Open Sci 2019 Feb;6(2):181078.
- Berman TS, Ben-Ari M, Glasser TA, Gish M, Inbar M. How goats avoid ingesting noxious insects while feeding.. Sci Rep 2017 Nov 1;7(1):14835.
- Gish M, Ben-Ari M, Inbar M. Direct consumptive interactions between mammalian herbivores and plant-dwelling invertebrates: prevalence, significance, and prospectus.. Oecologia 2017 Feb;183(2):347-352.
- Wills PJ, Anjana M, Nitin M, Varun R, Sachidanandan P, Jacob TM, Lilly M, Thampan RV, Karthikeya Varma K. Population Explosions of Tiger Moth Lead to Lepidopterism Mimicking Infectious Fever Outbreaks.. PLoS One 2016;11(4):e0152787.
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