At the Games, infected horses would have to be kept in extended quarantine, which would cost an estimated $1 million.

Fourteen of the infected 28 horses from Europe could compete under Irvin's plan.

The disease is primarily spread between infected horses.

The rate of infected horses approached 100%, and mortality rates ranged between 1% and 10%.

The disease is highly contagious, and can spread through the air as well as through objects that have been in contact with infected horses.

It ordered the euthanization of the 76 infected horses.

But they said they were concerned about the high mortality rate among infected horses.

Ms. Glaser found the state's first infected horse in May this year.

Four of these outbreaks have spread to humans as a result of direct contact with infected horses.