Mother Nature's Toxic Spill (Cont.)

And the Tests Go On
Agronomists and nutritionists Dr. Jimmy Henning (of the University of Kentucky), Roger Allman (The Farm Clinic), and Dr. Steve Jackson (Bluegrass Equine Nutrition) have taken a multitude of samples of pastures and hay for testing. Grasses such as orchard grass, bluegrass, fescue, and clover (a legume) have been individually harvested for testing. Powell said there are pasture samples from prior to May 5 that are very important to the investigation. "We can't take pasture samples now that reflect what was going on over that relatively short period of time," he explained.

Hay samples might contain the best clues as to what was growing, or not growing, among the pastures early this spring.

Tissue and biologic samples also have been taken and are being studied and tested. One very useful group of samples are the 130 bloods taken at the beginning of the outbreak (May 3). Results of preliminary testing on those samples should be completed in a few days.

One hormone that researchers are interested in monitoring is prolactin. Fungal endophytes and ergot alkaloids depress prolactin production in mares. This is why pregnant mares exposed to endophyte-infested tall fescue respond to domperidone.

While recommendations have been made by veterinarians in the field to use domperidone to prevent pregnancy loss, Powell said farms with late-term pregnancies using the drug didn't see much help in saving foals.

Other samples being studied include tissue samples from foals and fetuses taken to the Kentucky Livestock Disease Diagnostic Center, urine from affected mares, and colostrum collected at the time of the worst losses.

"The pathology of fetuses, particularly the lung, is providing interesting pathways to study," said Powell. But at this point, he added, "from a biochemical point of view, there are no significant changes."

Tent caterpillars were collected and frozen for future study. Teams also have been sent north to collect caterpillars because they are still active in those regions. Powell said those samples will be important to look for potential toxins.

And the Killer Is...
Powell said historically when these syndromes have happened, scientists weren't able to come up with an answer. However, he said the big difference this time is that everyone was made aware of the problem much closer to when the event occurred.

"We could organize resources locally and nationally to identify the problem," said Powell.

"I can't say categorically we'll come up with an answer. My philosophy all along is to be focused and objective. I do feel we are utilizing all resources available to us locally, nationally, and internationally to come up with an answer."

In looking to the future, Powell thinks that by working with the climate and weather researchers, "we can come up with a climatic predictor that even without the knowledge of what the cause is, we can develop useful recommendations."

In other words, if certain weather patterns occur in the future, scientists will alert the horse industry to take precautions.

The search goes on, with cooperation, caution, and continued good science the guideposts. Other trails might turn up cold in the search for an answer, but like any good mystery, one "break" in the case is all that might be needed.

Glossary of Terms for Foal/Fetal Loss Syndrome