Some compounds present in the environment, both from natural and man-made sources, can disrupt the delicate hormone balance necessary for reproduction in several species possibly including horses, according to Cynthia Corbitt Gulledge, PhD, of the University of Louisville’s biology department. Gulledge presented “Hormones and Anti-Hormones in the Environment: Relevance for Equine Reproduction” at the Hagyard-Davidson-McGee Bluegrass Equine Reproduction Symposium Oct. 23-26 in Lexington, Ky.

“Chemical confusion can result when environmental chemicals trick the body into thinking that they’re the natural ones,” she stated. Another problem is when environmental chemicals block the action of an animal’s hormones. She cited instances of infertility, subfertility, feminization of males, and altered puberty due to environmental chemicals/hormones that had been documented in other species. Her suggestion was that although this cause of reproductive dysfunction had not been studied in horses, it should be considered in cases of reproductive abnormalities with no apparent cause