PORTLAND, Ore. (AP) -- The state veterinarian's office says an Oregon horse that showed signs of a potentially fatal virus linked to a horse show in Utah had to be euthanized.
The veterinarian's office at the Oregon Department of Agriculture said the Clackamas County horse was the fourth confirmed case of equine herpes virus in Oregon since the outbreak linked to a national cutting horse show in Ogden, Utah.
Another horse in Clackamas County was the first reported case in Oregon but that horse and two others are not showing signs at this time.
The second case was a horse in Umatilla County that traveled in the same trailer with two horses returning from the show. Those two horses tested negative.
The third case was a Deschutes County horse that attended the Utah show.