Equine herpes virus confirmed in Plumas County
State officials reported this afternoon that California has two more confirmed cases of equine herpes myeloencephalopathy (EHM), including one case in Plumas County. That brings the total number for the state to 15.
Local sources say the Plumas case involves a horse in the Vinton area that attended the National Cutting Horse Association’s Western National Championships held April 30 – May 8 in Ogden, Utah, where officials believe the outbreak began. All of the confirmed cases in California are in horses that attended this event.
Six of the positive horses display neurological signs, but the other cases have only been febrile, said the California Department of Food and Agriculture (CDFA). All confirmed cases in California are under state quarantine.
One confirmed positive horse was euthanized after showing severe neurological signs associated with the disease while at the Kern County Cutting Horse Event May 13 in Bakersfield, state officials said.
A suspected case is currently under investigation. This horse did not attend the Ogden event, but did participate May 5 – 12 in the Rancheros Vistadores ride in Santa Ynez.
The confirmed cases in California are in the following 10 counties: Amador, 1; Glenn, 2; Kern, 2; Los Angeles, 1; Marin, 1; Napa, 1; Placer, 2; Plumas, 1; Shasta, 1; and Stanislaus, 3.
EHM is highly contagious, especially among younger horses that travel a lot and intermingle with other young horses, according to info from the CDFA. Symptoms can range from respiratory illness to severe neurological disease. Signs may include a fever over 102 degrees F, lethargy, decreased appetite and neurological symptoms such as lack of coordination, hind limb weakness and inability to stand.
Local horse owners are advised not to travel with their horses.