Source:  Statement

Pilchuck Veterinary Hospital, a major facility in the Pacific Northwest, has issued the following statement regarding the EHV-1 outbreak.

Important Update on EHV-1: Neurological Disease Outbreak

Currently both Colorado and California have issued statements concerning the multistate outbreak of Equine Herpes Virus - 1 neurological disease (EHV-1) associated with the National Cutting Association's Western National Championships in Ogden, Utah (April 30-May 8).

Confirmed cases have been reported in several Western states, including Washington. The true extent of this disease is not yet known, but it is reasonable to consider that there is currently an elevated risk of EHV-1. Horses with the highest risk are those that attended this event or those that have been in direct exposure with horses returning from the show.

Anyone who has concerns about exposure of a horse should use the following guidelines and contact a veterinarian for additional precautions:

Segregate potentially exposed horses from any non-exposed horses by at least 50 feet. The exposed horse should not have direct contact with other horses for 3 weeks. Stall cleaning and husbandry practices should be separate for the potentially exposed horses.
Take your horse's temperature rectally twice a day for 21 days from the time of exposure. If the temperature is over 102 degrees F, please contact your veterinarian immediately. A fever also generally precedes the development of clinical/neurological signs.
The preferred testing method is PCR analysis performed on a nasal swab and whole blood. This is only effective to identify horses that are actively shedding the virus.

Pilchuck Veterinary Hospital is urging people who have horses exposed directly at the Ogden show or subsequently to voluntarily isolate and observe those horses for the next 14 days. It is in the best interest of all our horses to contain this outbreak if possible. ...  We will continue to post updates on this situation as it develops.