The survey of 133 Central Kentucky farms was designed to identify risk factors, not causes, of mare reproductive loss syndrome, said Dr. Roberta Dwyer of the University of Kentucky Gluck Equine Research Center. As a result of the survey, a list of recommendations will be put forth in the next four to six weeks to help farm managers avoid risk factors in the future.
Some of the farms were heavily affected by reproductive losses, and some were not affected at all. The survey was done in cooperation with the U.S. Department of Agriculture, and involved about 200 people, including farm managers, veterinarians, volunteers, university personnel, and state and federal officials.
The survey not only confirmed preliminary theories put forth by researchers as early as July 2, but offered reassurance that some concerns by the horse industry were not associated with the early fetal losses and late-term abortions this spring.
Dwyer used an example to explain the difference between a risk factor and a cause of a problem. If 70% of people at a picnic become sick, and the majority of those ate the potato salad, then eating the potato salad was a risk factor. The cause of the illness--whether it was Salmonella, E. coli, or a virus--still needs to be determined, and researchers still need to find out how the contaminate got into the potato salad.
In looking at risk factors, the survey also helped point out protective factors that were common on farms that had little or no reproductive losses. The factors included not having caterpillars, and feeding hay to mares at pasture.
The survey also focused researchers' attention on areas that need further investigation. While black cherry trees were a common risk factor, those trees have been around the same pastures and paddocks for decades, if not centuries. The spring's distinct weather pattern and the presence of Eastern tent caterpillars--two risk factors already being studied as links to reproductive problems--were identified as links to the reproductive problems.
"The weather data will be closely monitored and thoroughly looked at in the spring so if this weather pattern comes again, we can warn horse owners," Dwyer said. "April was the driest in over 100 years, so we don't anticipate that (weather pattern) will happen again any time soon."
Dwyer said a survey of this magnitude and size usually would have taken up to a year to develop, implement, and analyze. Instead, the problems seen in Kentucky and other states took a priority for state and federal officials and researchers.
"Many people put their jobs aside to work on this full-time," Dwyer said.
From the first time the problem was brought to the attention of university personnel, it took only 20 days until the 11-page survey was ready to go to the farms. That included deciding on which questions were pertinent, selecting farms based on certain criteria, and organizing experienced volunteers to conduct the surveys in person.
Dwyer applauded the farms' cooperation in providing data. "Since we put the survey up on-line before we visited the farms, several already had all the information ready when we got to the farm," she said.
Data was entered into a database in an ongoing process by USDA veterinarian Barry Meade, who is based in Frankfort.
It took 20 days to complete the survey of 133 farms. By June 26, all the data had been verified. At that point, the Center for Epidemiology and Animal Health in Colorado took over the analysis of answers. Individuals at CEAH are experienced in developing and analyzing surveys of the animal industry.
Another survey of specific factors of about 300 individual mares should be completed and released in the next several weeks. That will look at such factors as age of mare, whether she was barren or had a foal by her side, and whether any medications used in the mares made a difference in reproductive losses. That also is a joint project between CEAH and the University of Kentucky.
The horse industry will continue to look toward state and federal officials, as well as private veterinarians, for emerging evidence that points to a cause or causes of the problems seen this spring.