Three cases of a virulent strain of the equine herpes virus have been reported in Washington state, prompting horse owners to take precautions against spread of the disease.
The Spokane Lilac Association reported today that seven of its 15 equestrian entries in Saturday’s Armed Forces Torchlight Parade have cancelled as a precaution.
Some of the area’s horses were exposed at recent competitions in Ogden, Utah, and Clarkston, Wash., said Mike Dedmon, vice president of parades for the Lilac Association.
“I’d rather stop the spread than have them coming here,” he said.
One of the Washington cases occurred at the Washington State University Veterinary Teaching Hospital.
That horse was admitted to the hospital for unrelated problems, but the virus was later detected. The horse had competed at the National Cutting Horse Association Western National Championships in Ogden about two weeks ago.
In a recent letter, State Veterinarian Leonard Eldridge said the infection was a variant of the Equine Herpes Virus (EHV-1) known to cause extreme neurological complications and death.
Voluntary quarantines, veterinarian monitoring and other precautions are recommended for horses that were exposed, he said.
Confirmed cases must be reported to the state veterinarian’s office at (360) 902-1881.
“This is a reportable disease,” said Charlie Powell, public information officer for the WSU College of Veterinary Medicine.
The WSU veterinary hospital has been under a voluntary quarantine, not accepting any new equine or camelid patients except in dire emergencies. Camelids include alpacas and llamas.
“This virus is so contagious,” he said. It spreads through sneezing, whinnying and other contact. The virus can survive on tack gear or even shovels to infect other horses.
Its incubation period is two to 14 days.
Powell recommended that horse owners voluntarily limit travel for the next few weeks so the outbreak can be stemmed.
Humans, livestock and pets are not at risk, Powell said.
In Colbert, the McKinlay & Peters Equine Hospital treated a horse that had symptoms of the disease, but that horse was sent home for quarantine and the hospital is under quarantine and taking precautions.
The horse had been at one of the competitions to which the virus was traced, a spokeswoman there said. The hospital was awaiting results of a lab test to determine if the horse was infected.
Lilac officials are taking steps to protect horses during the parade. A veterinarian will be on hand. Equestrian entries will be spaced at least 50 feet apart in staging areas.
Dedmon in a letter to equestrian entrants asked that horses that attended the Ogden event to stay home.
In the Spokane area, stable owners are taking steps to halt the spread of the disease.
At Valley Chapel Farms south of Spokane, owner Lisa Talbott notified horse owners that the facility was closed to incoming horses and asked that horses at the farm be kept there for the next two weeks as a precaution.
She said she is not concerned about the virus spreading there because “we are more of a recreational facility” rather than a stable for competitive horses.
However, she noted in an email that almost all horse events have been canceled for the time being and many stables have been “locked down.”
The Kitsap Sun reported that equestrian entries were pulling out of Bremerton’s Armed Forces Day Parade on Saturday.
One of the confirmed Washington cases was reported in Snohomish County.
The neurological strain of EHV-1 was first identified in 1971. Treatment is available, but may or may not be effective, Powell said.
For more information, the U.S. Department of Agriculture has a guide to understanding the neurological form of EHV infection. Also, go to vetmed.wsu.edu/.