LAS VEGAS - Nevada agriculture officials are warning horse owners about possible exposure to a deadly and infectious virus, though no cases have been reported in the state.
State Veterinarian Phil LaRussa said in a Tuesday memo to horse owners and veterinarians that the Equine Herpes Virus-1 traced to an outbreak in Utah is a severe strain spread by air and by contact with humans.
The disease poses no threat to people. But it is easily spread among horses, alpacas and llamas by touch or by sharing feed, brushes, bits and other equipment.
LaRussa says the National Cutting Horse Association has notified owners who participated in the Western National Championships last month in Ogden, Utah.
LaRussa says horses that participated in the competition should be monitored for signs of disease.
So far, at least 17 horses in Idaho, Utah, Colorado, California, Washington and Canada have been infected with the highly contagious Equine Herpes Virus-1, and at least three have died.
The infected horses were among roughly 400 that attended the National Cutting Horse Association event.
Officials in several states are quarantining infected animals and asking owners of other horses that were at the event to closely monitor the animals for symptoms. Organizers also are cancelling horse shows and classes in Texas, Utah and elsewhere in an effort to stem the disease's spread.
The outbreak has horse owners across the West worried, said Preston Skaar, president of the Idaho Cutting Horse Association.
"It's a hard deal, but all you can do is have your horses stay home and wait it out," he said.
Skaar took one horse to compete at the Utah event and then brought it back to his property in Menan, Idaho, where it lives with 12 other horses. So far, he said, none of the animals have shown any signs of illness, but he's starting each day earlier so he can take their temperature and check for fever, gait problems and other symptoms of the virus.
Infected horses can appear perfectly healthy until they get stressed and the virus takes hold, he said - so none of the horses are being ridden unless absolutely necessary.
"I was kind of bummed out that I didn't make the finals (at the Ogden competition), but I'm not feeling quite as bad about it now," Skaar said. "That kept my horse from getting more stressed and fatigued, and maybe that helped."
Officials with the National Cutting Horse Association couldn't be immediately reached, but a statement on the group's website said members are closely monitoring the situation and that all NCHA-approved shows scheduled for this weekend have been canceled by the affiliates or show producers putting on the events.
"The NCHA appreciates this proactive move by show producers in a nationwide show of precaution and solidarity," the group said. "While reported cases of the virus are currently in Western states, the interstate transport of infected horses could cause a much wider spread of the virus if we are not all very cautious at this time."
The virus can usually survive for about a week on surfaces, Idaho veterinarian Bill Barton said, though under the right conditions it could last as long as 30 days. That makes it particularly tricky to fight, because even the snort of an infected horse could spray nearby equipment or feed with the virus, said Debra Sellon, a veterinarian at Washington State University's Veterinary Teaching Hospital.
Infected animals usually get sick between two and 14 days after they are exposed to the virus. Symptoms include fever, sneezing, staggering and partial paralysis.
