09/27/2001 11:00PM

Solving the mystery of grass sickness


LEXINGTON, Ky. - Sheikh Mohammed al Maktoum, whose champion Dubai Millennium died of grass sickness at age 5 this year, has established a research project into the mysterious disease. The project, which is based in Dubai, United Arab Emirates, but involves scientists from around the world, aims to develop preventive measures for the disease within five years.

Meeting in the United Arab Emirates on Sept. 23, a group of 16 scientists identified two primary research tracks: identification of the disease's cause and development of a vaccine.

Grass sickness, a frequently fatal disease that paralyzes the equine digestive system, strikes about 200 horses annually. It occurs most often in grass-fed horses in northern England and Scotland, where it was first identified in 1906.

Its exact cause is unknown, though scientists in England have pointed to clostridium botulinum bacteria, which are present in soil and water and cause botulism, as a leading suspect. Another theory focuses on cyanide from white clover in pasture.

Dr. Ulrich Wernery, scientific director of Dubai's Central Veterinary Research Laboratory, is in charge of the project.

"The great thing is that now we've pooled our knowledge," Wernery told Gulf News. "We have been able to discount several other factors it was thought were possible causes of the disease. Previously, pesticides, fungal toxins, herbicides, and plant toxins were all under suspicion but can now be excluded."

"What we are aiming to do is find preventive measures for the disease rather than a cure, because once the illness is diagnosed, irreversible damage has already been done," said Dr. James Wood, chief of epidemiology for the Animal Health Trust in England.

Among the researchers attending the conference was Dr. Peter Timoney, director of the University of Kentucky's Gluck Equine Research Center in Lexington, Ky.

West Nile spreads

Louisiana has become the most recent state to detect West Nile virus in its horses, according to statistics issued by the United States Department of Agriculture. A single horse in Vermilion Parish has tested positive for the mosquito-borne disease, which can be fatal to both humans and horses.

Since first arriving in the western hemisphere in 1999, West Nile has killed 11 people and at least 53 horses.

The affected horse in Louisiana was a 7-year-old Quarter Horse mare who went down on Aug. 21 and was unable to rise. The mare was euthanized on Aug. 23.

A month earlier, a dead blue jay in Jefferson Parish outside New Orleans tested positive for West Nile virus.

As of Sept. 5, the USDA reports that there have been 66 clinical cases of West Nile virus in horses this year, and at least 17 of those horses have been euthanized.

Predicting injury

Scientists at Colorado State University have reported that preliminary data from a research project there suggests that certain serum markers in equine blood may help predict some bone injuries.

According to a summary that researcher Dr. David Frisbie provided to the Grayson-Jockey Club Research Foundation, which was supported by three equine insurance companies in funding the research, early indications are that "although serum marker levels are elevated by the very act of athletic training, even higher levels are seen in problem status - allowing a distinction between normal and abnormal to be made."

Those results may mean that some injuries, like knee chips, might be predicted by blood tests. So far in the study, which involves some 200 horses in training in California, researchers say they have been able to successfully detect the presence of knee chips 75 percent of the time.

*British veterinarian Dr. Robert Eustace has launched a new web site offering advice about prevention and treatment of the hoof ailment laminitis. The site is at www.laminitis.org.