Epidemiologist Q&A on Excessive Foal Losses

Dr. David Powell, an epidemiologist at the University of Kentucky's Veterinary Science Department in the Gluck Equine Research Center, was interviewed Monday by The Blood-Horse about the unusually high number of early fetal loss and late-term abortions among broodmares at Central Kentucky farms. Following are transcripts of the interview:

Q: Where are the Gluck Center researchers concentrating their efforts right now?
A: In terms of the investigation, there's a lot going on at the Diagnostic Lab (where the aborted fetuses are necropsied), concentrating on the possibility of an infectious disease agent. The other aspect being closely monitored is the possibility of some toxin in pasture. We had a meeting this morning with various individuals in pasture management, and there is a whole array of samples that have been taken and will be taken to see if there is a factor in the pastures that is contributing to this problem. It also includes looking at other aspects, including the phenomenal increase in caterpillars, or any other avenues.

Q: Is this just a problem in Central Kentucky?
A: I just received other information that this problem does not seem to be restricted to Kentucky. It's possible mares in other states (north of Kentucky) may be experiencing a similar syndrome. We are looking at that and clarifying it. If that is true, it suggests we are not dealing with an infectious disease, although we can not necessarily rule that out. I think we can rule out a contagious disease. My personal observation would be, based on the sudden nature of this over the last week, that it doesn't suggest we are dealing with a contagious disease.

Q: In 1980, The Blood-Horse reported a similar situation with increased abortions at Central Kentucky farms. That year, an unusually cold night in early May left a covering of frost in the region, and there was speculation it created a toxic substance. Are there similarities between the two occurrences?
A: The syndrome, particularly the early fetal loss, was very similar to 1980. Nobody was examining mares by ultrasound in 1980, so the condition is being picked up earlier now than in 1980. Unfortunately, the numbers seen currently are greater than what was reported in 1980. The factor that many feel is contributing to this are the climatic circumstances over the last month -- very low, or no rainfall, and a sudden spurt of very high temperatures. We are now checking the weather patterns to see if the same conditions existed then.

Q: Why were they unable to draw any conclusions as to the cause then?
A: The possibility of pasture toxin was in the back of peoples' minds, but there was no solid conclusion.

Q: What is known now that wasn't known then?
A: In terms of what we know that can contribute to this situation, we know very definitely that fescue can be a problem, but we are seeing this condition on farms where there is little or no fescue. That's not to say there is no endophyte or toxins in other strains. We are not just restricting our investigations into fescue toxins. We are looking at other pasture grasses. What we can say as far as the abortions are concerned, we have no evidence that it is caused by herpesvirus.

Q: Short of a definitive answer, what is the leading theory about cause?
A: Our consensus, based on the pattern of the syndrone as it emerges, is we are looking more at a very common factor that has evolved over the last two or three weeks. At the moment, it's very widespread. We have sent out a questionnaire to every farm requesting information on losses in relation to number of mares covered, number of mares foaling. We hope to have the information by (May 9), and we think that will give us a better picture. We hope to be able to report the results of that information at a meeting on the following day. (The Kentucky Thoroughbred Farm Managers' Club and the Kentucky Association of Equine Practitioners will hold a joint meeting Thursday, May 10, in the Keeneland sales pavilion near Lexington to discuss the situation. The meeting will begin at 5 p.m.)

Q: Is there anything you can add?
A: From an industry perspective, we've got to hang in there, keep our heads cool, and we will work our way through this. The cooperation we are getting is very positive at the moment.