Mare reproductive loss syndrome returns, but losses are fewer.

The research article discusses the return of the mare reproductive loss syndrome (MRLS) in the equine industry, which caused fewer losses than the previous year. The article presents research findings pointing to the eastern tent caterpillar as the culprit of this syndrome.

Overview of Mare Reproductive Loss Syndrome (MRLS)

• MRLS is a devastating condition that affected the equine industry heavily in 2001, leading to the death of numerous foals and causing a high number of spontaneous abortions.
• The syndrome reappeared in the following year, but with fewer losses reported. The Livestock Disease Diagnostic Center reported 270 aborted equine fetuses between April 28 and May 25, 2002, as compared to 495 in 2001.
• The researchers were unable to conclusively say what causes MRLS, though evidence collected during this study points towards the eastern tent caterpillar as the source of the problem.

Role of Eastern Tent Caterpillar in MRLS

• According to Dr. David Powell, veterinary epidemiologist at the University of Kentucky’s Gluck Equine Research Center, the correlation between the presence of the eastern tent caterpillar and the occurrence of MRLS is evident. Cases were only reported on those farms or pastures where the eastern tent caterpillar was present.
• In farms where there were no caterpillars, no case of MRLS was reported for that year.

Experimental Evidence

• A series of experiments at the University of Kentucky also implicated the caterpillar. In a particular experiment, pregnant mares were divided into different groups and exposed to caterpillars, frass (caterpillar waste), or neither.
• Findings from the study showed that a higher number of abortions occurred in the groups exposed to caterpillars and frass, compared to the control group that was not exposed to either.

Conclusion

• Based on the patterns observed and the results from the experiments, the research strongly suggests that the eastern tent caterpillar plays a significant role in causing MRLS.