CORVALLIS, Ore. - An outbreak of Equine Herpesvirus-1 in several western states has raised concern that this disease that affects horses, llamas and alpacas may become a problem in Oregon. And on Wednesday afternoon, the state veterinarian announced that the first case had been diagnosed in Clackamas County.

An informational meeting will be held by the College of Veterinary Medicine at Oregon State University on Thursday, May 19, from 6 to 7 p.m. The public is invited to the meeting, which will be held in Magruder Hall 102. Magruder is located at 30th Street and Washington Way in Corvallis, just west of Reser Stadium.

Equine Herpesvirus-1, or EHV-1, can cause neurological damage, respiratory problems, abortion and neonatal death in horses and camelids. Though many animals may carry the virus, it generally remains inactive until triggered by stress, including excessive exercise, during long-distance transport, or at weaning.

EHV-1 is the primary cause of equine herpesvirus myeloencephalopathy, which is considered an "emerging disease" that causes damage to the blood vessels in the brain and spine and can be fatal. Outbreaks have occurred at large horse facilities and events - including race tracks, horse show grounds, and boarding stables.

OSU veterinary officials say EHV-1 is spread primarily from horse-to-horse contact, but can also be transferred via indirect contact, especially from infected tissues from fetuses and fetal membranes.

"Horses can appear to be perfectly healthy yet spread the virus via secretions from their nostrils," said Helen Diggs, director of the Veterinary Teaching Hospital at OSU.

Keeping feed and water buckets, grooming equipment, tacks, and even human handlers clean can help prevent the spread of EHV-1.

Signs of EHV-1 include fever, decreased coordination, incontinence, loss of tail tone, hind limb weakness, leaning against walls or fences to maintain balance, lethargy and inability to rise.

In this latest outbreak, EVH-1 has been diagnosed in California, Washington, Idaho, Colorado and Utah.

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Helen Diggs, 541-737-6462