LOUISVILLE, Ky. - The major provider of insurance for Kentucky's horse industry has temporarily stopped writing policies that cover dead foals. Lloyd's of London said it will halt policies until it knows more about the mysterious illness killing foals in the state.

As of noon Tuesday, 468 aborted or stillborn fetuses and foals had been submitted to the University of Kentucky Livestock Disease Diagnostic Center since April 28.

Researchers are still searching for a cause of the illness -- termed Mare Reproductive Loss Syndrome. Scientists have focused their research on possible mycotoxins produced by fungus in pasture grass.

For the moment, writers of foal insurance "are like a home insurer in the middle of a forest fire," said Julian Lloyd, chairman of Lloyd's of London's livestock committee.

"I would find it very, very surprising if anybody was actually writing fetus policies at the moment," Lloyd said.

Insurance agents in Kentucky agreed that foal insurance "for now is unobtainable, basically," in the words of Alex Rankin, an equine insurance broker in Louisville.