Kentucky is grappling with the disastrous consequences of hundreds of pregnant mares on its prestigious horse farms losing their foals in the past two weeks.
The resulting loss could be in the tens of millions, if not hundreds of millions, of dollars for the horse-breeding industry.
In Maryland, which will be the host of the Preakness on May 19, no trace of the foal loss syndrome has been found, according to state and horse industry officials.
Mares of all breeds in Kentucky are giving birth to stillborn foals or experiencing early spontaneous abortions. The deaths are being widely attributed to an unknown disease that might have originated in a fungus in the state's famous bluegrass, veterinarians say.
Kentucky is the center of the U.S. horse-breeding industry, valued at $900 million a year.
"The losses will certainly be in the millions," said Craig Bandaroff, proprietor of the Denali Stud farm in Paris, Ky., where 55 broodmares are housed.
More than 10,000 mares breed or give birth to foals each year in Kentucky, which accounts for one-third of the country's thoroughbred racehorses.
Since April 28, 371 aborted or stillborn fetuses have been brought into the Livestock Disease Diagnostic Center at the University of Kentucky for examination. Twenty-five of those were submitted Wednesday morning and 28 the day before. That is six or seven times higher than the number usually seen at this time of the year, veterinarians say.
There have been reports that some farms have lost as much as 75 percent of their expected foal crop and that Kentucky's breeding industry might suffer more than a 30 percent reduction in the number of horses born next year.
The ripple effects could be felt for years. Stallion owners typically collect fees only on a "live foal" basis, or when the foal stands and nurses, meaning millions in stud fees will go uncollected.
Middlemen such as Bandaroff, who in addition to boarding mares help arrange the sale of young, unraced horses, will have fewer horses to sell. Bloodstock agents, who buy and sell horses, and feed producers will be affected, too, and racetracks might also feel a hit.
"At this stage, we do not have a definite diagnosis as to what is causing" the problems and are doing a thorough investigation, said Dr. David Powell, an equine epidemiologist at the Maxwell Gluck Equine Center at the University of Kentucky.
Officials in Maryland said they are monitoring the situation closely.
Donald H. Vandrey, a spokesman for the Maryland Department of Agriculture, said that Dr. Roger Olson, the state veterinarian, had considered an embargo that would have prohibited horses from Kentucky coming into Maryland.
"But we have decided not to do that at this time," he said. "There has been no trace of a problem in Maryland."
But some Maryland horse breeders remain concerned. One is Michael Pons with Country Life Farm in Bel Air.
"I have three of my best mares in Kentucky," Pons said. "It's high anxiety time."
Despite his concerns, Pons said he is not planning sudden action. "I will leave them there short term. I may bring them back in a week or 10 days, but I'm going to wait until the dust settles."
Pons said he was in Kentucky over the weekend and met with the manager of the farm where his mares are boarding. "They have taken the horses out of pasture and are feeding them grain," he said.
Tim Capps, executive vice president of the Maryland Horse Breeders Association, said the "attitude among most Maryland horse breeders is pretty much uniform. They are not doing anything, they are not trying to bring their horse back until they are clear about what is causing this."
"If it's a virus, which is highly unlikely, you would not want to bring the horses back and spread the disease."
Sun staff writer Ted Shelsby contributed to this article.