April 25, 2002 | By: Haven Miller

A study of pregnant mares that did not lose their foals during last year's occurrence of Mare Reproductive Loss Syndrome has brought welcome news to Kentucky's horse industry.

The study, which was a collaborative project between Hagyard-Davidson-McGee Associates and the University of Kentucky College of Agriculture, involved examination of pregnant Thoroughbreds on eight central Kentucky farms. Of 91 mares, 58 were known to have been exposed to MRLS during 2001 and 33 were not exposed.

Results indicate MRLS had no effect on incidence of fetal loss, fetal abnormality, and placental and foal weight at birth.

"In this study we did trans-abdominal ultrasound with mares that were pregnant around 130 days and followed those mares until they foaled," said Lucas Pantaleon, veterinarian with Hagyard-Davidson-McGee. "We didn't find any significant differences between the mares exposed to MRLS and those that were not exposed."

Mares selected for the study were bred between February 1 and March 15, 2001. Mares were identified as "exposed" to MRLS if they had been pastured together with horses that had lost their pregnancies due to MRLS. Those that had been pastured among mares that had no losses from MRLS were identified as "not exposed."

"I think this study is an excellent example of how the various groups in our equine industry are working together to solve this particular problem," said David Powell, equine epidemiologist with UK's department of veterinary science. "The results of this study are extremely encouraging."