A deadly virus is spreading among horses in the Western United States and parts of Canada. The highly contagious equine herpes Virus-1 isn’t a threat to humans. But it spreads easily among horses — and even llamas and alpacas.

So far, it’s caused scores of horse owners to quarantine their animals. It’s also forced the cancellations of horse shows and competitions.

Becca Francis has trained horses for cutting competitions her entire life, so it’s routine for her to spend afternoons mucking out stalls at her training facility northeast of Denver. But what’s not routine is dipping her soiled boots in a bucket of bleach water each time she moves from stall to stall in this barn.

“Probably one of the things is just keeping everything sterile and separate from other horses,” Francis says, “which if you’ve ever been in a horse barn is a hard thing.”

Clorox and rubber gloves are Francis’ new reality. That’s because the state of Colorado has quarantined this facility. It wants to head off the deadly EHV-1 virus that’s threatening horses across the West.

Francis had three prized horses contract the virus after attending a recent National Cutting Horse Association championship event in Utah. Two are recovering, but one had to be euthanized.

“I’ve never, ever heard of anything like this, nor ever thought it would be a concern I’d have to face,” she says. “So it’s an eye-opening experience, for sure.”

About 600 horses attended the Utah event, where the outbreak is believed to have started. But its symptoms weren’t detected until later, in a horse in Colorado.

“The size and the extent of the outbreak is unprecedented,” says Dr. Keith Roehr, Colorado’s state veterinarian. He says EHV-1 has become common only in the past few years.

The disease starts as a respiratory virus; most horses recover in a few days. But in others, the virus becomes active in the brain and spinal fluid, where it becomes life-threatening. That’s why there’s so much concern.

“The disease can be spread from horse to horse,” Roehr says. “We also know that the disease can travel on hands, on boots, on clothing, equipment or feed, so it can be spread indirectly.”

Colorado officials aren’t taking any chances. Horses entering the state have to have a permit, and horses traveling within it must have a vet-signed health certificate. Officials from Wyoming to California are taking similar steps.

Most horse shows or competitions have been canceled or postponed, including one of the largest in the United States: the annual Breeders Invitational in Oklahoma. The event’s director, Robert O’Bannon, says the decision wasn’t made lightly.

“There is some degree of overreaction,” he says. “But the fact that all these other events are being canceled, to me, just validates that decision.”

O’Bannon points out there’s a huge economic impact when horse shows are canceled: Vendors and judges don’t come, and hotel rooms and restaurants empty. In fact, the American Horse Council says that horse shows are a $39 billion annual industry.

Veterinarians say the only way to stop the disease is to vaccinate horses against EHV-1 — and in this case, to try to limit the spread from the horses that attended the Utah event.

Taking a four- to six-week hiatus from competitions is a sacrifice that Francis, the trainer, is willing to make.

“No competition is worth what we’re going through,” she says.

It’s costing hundreds of dollars a day to treat the rest of her horses with anti-viral drugs. But she says that money is definitely worth it, given the financial hit she’d take if more horses were to fall ill and die. Copyright 2011 KUNC-FM. To see more, visit http://www.kunc.org.