May 12 Update: Foal Loss Appears to Be Slowing

By Kimberly S. Graetz

As the breeding season winds to a close, you expect to see fewer foals being born. Therefore, there are fewer chances for the current syndrome to affect late-gestation mares. It also seems, however, that the loss of late-term gestations--and early fetal loss--could be slowing overall.

The Kentucky Livestock Disease Diagnostic Center as of noon Friday, May 11, had an additional 22 aborted/stillborn equine fetuses/foals for diagnostic testing/evaluation submitted that day. The total submitted since April 28, 2001, is 404.

Dr. Roger Murphy, a private practitioner and president of the Kentucky Veterinary Medical Association and the Kentucky Association of Equine Practitioners, said he's had two normal foals in the past few days that are doing well. He said the pregnancies viewed via ultrasound early last week that were compromised pretty much are gone now (abortions resulted). But the mares checked yesterday and today are still pregnant.

He added more good news in reporting that the host of mares which have been bred recently are all pregnant and seem normal.

"In my practice, things are stabilizing," Murphy said. "Things are quieting down."

He said that more good news is that pregnant mares shipped to Illinois and Minnesota have been scanned and are still pregnant and normal.

Murphy said most people are still keeping mares in, because of an assumption that the problem is pasture-related. He said some of his farms have had pastures sampled, and they are awaiting the results to see if a mycotoxin is the culprit.

The general thought and pattern seems to have been that mares bred from the start of the season through early March and were 30-40 days or more pregnant when the "insult" hit in April were the ones which lost their pregnancies. The mares which were 50 or more days pregnant when they lost their pregnancies are nearly impossible to successfully re-breed because of the formation of endometrial cups.

"We're checking everything every five days, but we're not getting those ecogenic particles in the fluid (around the embryo) like before," said Murphy of his ultrasound exams.

Many people have seen unusually high incidence of sore feet on horses, but Murphy thinks that is just because of the hard ground from the drought.