During late April and May of 2001 and 2002, the bluegrass area in the central part of Kentucky experienced an epidemic of equine abortions. Early fetal loss (days 35–100 of gestation) and late-term abortion occurred in recently bred mares and mares nearing foaling, respectively. These losses have been termed mare reproductive loss syndrome (MRLS). For the period, estimates placed the economic loss due to MRLS at over $330 million.