05/31/2011 04:53 pm ET Updated Jul 31, 2011

Horse Herpes Outbreak In Western States

Horse owners across the Western United States are grappling with a highly contagious and fatal disease -- Equine Herpes Virus 1, or "horse herpes."

The virus, which affects only equine animals, causes clear discharge in the nose, sudden high fevers, fatigue, disorientation, and even abortion. It is an airborne virus but can also be spread through contact with contaminated equipment and clothing, according to a statement from the the United States Department of Agriculture. Humans aren't affected by the disease, but mules, donkeys, llamas, alpacas, and camels can contract it.

Authorities agree that the virus broke out at a horse event in Ogden, Utah in late May. It then spread to nine Western States, as well as Canada. As of last Friday, there were 75 confirmed cases and 61 facilities suspected of being infected, according to the Associated Press.

Because the virus can be fatal, horse riding competitions have been cancelled in the wake of the outbreak, and horse owners are reluctant to bring their animals to events -- even when event organizers insist there is no danger.

This past weekend in Burbank, California, attendance was halved at the annual Memorial Day Classic at the Los Angeles Equestrian Center. A spokewoman for the event told the LA Times that misinformation was responsible for the decline, stating, "It is impacting the show in a very negative way, but we are confident that we are not placing any horses at undue risk." Meanwhile, the virus has since been found among thirteen horses in San Diego who were present at the event in Ogden, Utah, reports KTLA.

Horse owners are advised to quarantine their horses if they show signs of the disease, and to keep healthy horses away from potential contamination. Veteranarian Tanis MacDonald, DVM, has written a blog post of recommendations on how to prevent the disease:

The first step in prevention of EHV-1 is to take a deep breath, and STAY HOME. There is no such thing as an Emergency Horse Show. This is not the time to go visit your friends down the street with horses. This is not the time to load up and meet 20 different trailers at a trail ride and head out for the day. The BEST way to prevent EHV-1 exposure is to quarantine your horses and barn from other equine traffic.