(IDAHO FALLS) – A national horse show just a few weeks ago is causing some major problems for horse populations around the country, including Idaho. At least two Idaho horses have confirmed cases of Equine Herpes Virus-1. Experts say the virus causes nasal discharge and loss of balance among horses, and has a high mortality rate. Earlier this week Nebraska officials quarantined five ranches known to have infected horses. Idaho officials have not released the locations of the animals infected within the state.