Since then numerous scientific trials have taken place to try and ferret out the cause of MRLS. Researchers have repeatedly proven a link between the presence of Eastern Tent Caterpillars and symptoms of MRLS, but the exact cause of the syndrome is still unknown. Two approaches to solving MRLS are now being pursued, according to a release detailing the Think Tank meeting. One approach hypothesizes that a biologic agent associated with the caterpillar, such as a virus or bacterium, is the cause. The second theorizes that the caterpillars contain a toxin or chemical agent which, when exposed to pregnant mares, can cause late-term abortion or early fetal loss.
The University of Kentucky's Livestock Disease Diagnostic Center reports a slight rise in the number of equine abortions reported from Jan. 1-14, compared to the same time period last year. Since Jan. 1, 68 abortions have been reported and examined, compared with 53 for 2002. The report comes less than a week after 31 veterinarians and scientists met in Central Kentucky for a "Think Tank" meeting on mare reproductive loss syndrome (MRLS) and discussions on its prevention. The meeting, held Jan. 10, included participants from several states and universities. That group concluded that further research on the Eastern Tent Caterpillar and its role and link to MRLS is a priority. MRLS was first identified and named in Central Kentucky in May of 2001. That year more than 500 later-term abortions were reported and those fetuses submitted, while approximately 3,000 Thoroughbred mares lost their 2002 pregnancies early in gestation.