Researchers investigating mare reproductive loss syndrome (MRLS) have made a causative link between the ingestion of live eastern tent caterpillars in pastures and MRLS-type abortions. A panel of five researchers from the University of Kentucky, Lexington Livestock Disease and Diagnostic Center, Venture Laboratories, and Cornell University presented their findings Wednesday during a Kentucky Thoroughbred Owners/Breeders Foundation forum at Keeneland. Dr. Karen McDowell of the University of Kentucky characterized several landmarks and milestones in recent MRLS research. She cited the identification of bacteria associated with MRLS and how the lesions found on MRLS-related abortions differ from non MRLS-related abortions. McDowell also said an epidemiological survey found caterpillars on farms in high numbers were associated with fetal loss. She added that because they were associated or correlated didn't necessarily mean they caused the losses. Another milestone, according to McDowell, was identifying and typing the bacteria present and definitively matching the bacteria from the mare's gastrointestinal tract, particularly the oral cavity, with the bacteria isolated from the aborted fetus. She said that told researchers those bacteria have come from the oral cavity of the mare. "Even if you can give mares bacteria and show it directly and show those bacteria do affect the fetus you still have to have a model for how those bacteria get from the mare to the fetus," she said. "In my mind that is something that really needs to be shown. I think we will get there."In addition to the landmarks made in research, Dr. Bruce of Webb of the University of Kentucky is researching new ways to control the caterpillar population instead of cutting down all cherry trees. Dr. Don Schlafer of Cornell University is developing a model to directly look at blood flow and toxins to the fetus.