A research project has identified an association between Eastern tent caterpillars and early fetal loss in mares (see https://thehorse.com/ViewArticle.aspx?ID=3634). Principle investigators in the study were Bill Bernard, DVM, Dipl. ACVIM, a specialist in internal medicine, and Michelle LeBlanc, DVM, Dipl. ACT, a specialist in equine reproduction, both at Rood and Riddle Equine Hospital in Lexington, Ky.; and Bruce Webb, PhD, a specialist in entomology at the University of Kentucky. (Others involved in the research are listed in the article linked above.)

Following are some questions and answers from Bernard and LeBlanc about the research.

Q: Why did you do this study?

Bernard: Because of the importance to the industry to show what is causing MRLS (mare reproductive loss syndrome). It was initiated by dr. Webb’s field trial that suggested caterpillars or frass (excrement) was associated with early fetal loss. But from that project, you couldn’t tell if it was the caterpillars, the frass, or maybe something in the grass. (Webb’s study was done in enclosed grass pens)