OREGON STATE UNIVERSITY

Concern Over Equine Herpes Virus Prompts Informational Seminar at OSU

08/08/2007

CORVALLIS, Ore. – A horse suspected of having a highly contagious respiratory virus called Equine Herpes Virus-1 was treated at the Lois Bates Acheson Veterinary Teaching Hospital at Oregon State University and though results of the tests were inconclusive, numerous Oregon horse owners have called OSU seeking more information.

OSU’s College of Veterinary Medicine will hold a free public informational seminar on Equine Herpes Virus-1 on Wednesday, Aug. 15, in Magruder Hall Room 102 beginning at 7 p.m. Magruder Hall is located on 30th Street just south of Washington Way in Corvallis.

John Schlipf, a large animal internist with the college, will present basic information about EHV-1 and will team with fellow OSU veterinarians Anna Firshman, Erica McKenzie, Jaime Hustace and Katelyn Romeo to answer questions.

Earlier this year, an Oregon horse was confirmed with EHV-1, which can cause paralysis and abortions in pregnant horses. State Veterinarian Don Hansen issued a recent alert urging caution by horse owners after five horses in Washington also exhibited clinical signs consistent with the virus.

Schlipf, who specializes in equine physiology and disease, says Equine Herpes Virus-1 is “something to be conscious of, but not go into a panic over.”

“It is highly contagious, but it doesn’t last long in the environment,” Schlipf said. “Horse owners can apply a little common sense and drastically reduce the chances of EHV-1 infecting their animals. It has been seen more commonly in other states – like Ohio and California – recently, but hasn’t seemed to take a foothold in Oregon.”

The virus is not known to have a harmful impact on humans.

Equine Herpes Virus-1 is a virus that most commonly manifests as a respiratory disease in horses and is not necessarily serious, Schlipf said. However, through genetic mutation, it can cause a neurological form that can be life-threatening to horses. In its neurological form, which may be brought on by stress, EHV-1 causes injury to blood vessels, cutting off the supply of blood to areas of the spinal cord.

“It can end the athletic career of a horse,” Schlipf pointed out.

A nasal discharge is one sign of the virus, but a nasal discharge may also result from other viruses and allergies, just as in humans. Fever, malaise and nasal discharge are common clinical signs of EHV-1 infection.

Transmitted by aerosol, EHV-1 can move from horse to horse through transferal of nasal secretions. Horses nuzzling each other, or nuzzling humans who then touch other horses, can spread the disease. However, the virus doesn’t last long in the environment, researchers say.

Schlipf says concerned horse owners can do several things to ease their concerns:

• Monitor temperatures of horses and look for prolonged fevers;

• Limit contact of horses with others from fairs and shows;

• Be aware that humans can spread the virus to horses through contact with infected horses;

• Isolate horses that have fevers and nasal discharge from other horses;

• Consider isolating horses that compete in shows from other horses.

The horse tested at OSU, which came from the Willamette Valley, showed clinical signs of EHV-1 but laboratory technicians never recovered the virus during a polymerase chain reaction (PCR) assay. An Oregon horse tested in the spring was found to have had the disease.