The Humane Society of the United States urged the Bureau of Land Management to "discourage and, if possible and appropriate, prohibit" owners of private horses from bringing animals at risk of Equine Herpes Virus-1 onto federal lands where they could have contact with wild horses.
"The potential for a catastrophic outbreak of EHV-1 among wild horse herds needs to be addressed by the BLM on an emergency basis," Holly Hazard, the society's chief innovations officer, wrote in a letter to BLM Director Bob Abbey.
The federal agency should launch a public education campaign immediately about the highly contagious disease, which has infected dozens of horses and killed at least nine, as officials plan horse-related activities for the upcoming holiday weekend, she said.
EHV-1 poses no risk to humans, but can be fatal to horses. It can be airborne and transmitted by touch or by sharing feed, brushes, bits and other equipment.
So far, no animals managed by the BLM are known to have been infected, BLM spokesman Tom Gorey said Thursday. He said the agency is considering limiting horse movement on a case-by-case basis and may cancel some scheduled adoption events.
Horse owners should contact local BLM offices to see if there are any restrictions before bringing domestic horses onto federally managed public lands.