SAN JUAN CAPISTRANO – Two more horses at Rancho Sierra Vista Equestrian Center have the potentially deadly virus known as neuropathogenic equine herpes virus-1, bringing the total number with the disease to 11, state officials said late Tuesday afternoon.

Officials from the California Department of Food and Agriculture also said that a horse with the virus that became lame in the hindquarters and was euthanized last week did not become lame because of the disease.

The virus, which presents with coldlike symptoms including fever and nasal discharge and can cause neurological damage, has been confirmed in horses only at Rancho Sierra Vista. three other equestrian centers in the area between Junipero Serra Road and Ortega Highway near I-5 have been unaffected. nearly 1,000 horses live in the area.

Of the 11 horses with the virus, only one has displayed neurological symptoms, but it has started to improve, state officials said.

The Rancho Sierra Vista stable is under quarantine and will remain so for three more weeks, officials said.

Dr. Kent Fowler, animal-health branch chief at the Food and Agriculture Department, talked to horse owners and veterinarians at Stone Field Park on last week. About 100 people attended. Fowler talked about the illness and the precautions being taken.

“The disease typically has low mortality and can range from 0 to 30 percent,” he said after a news conference. “The symptoms can progress to a situation where the horse could die. We generally know how a horse will progress in a time frame of two weeks.”

Fowler said the disease must be reported to his agency within 48 hours. the virus is contagious, which is why the agency put the quarantine in place, he added.

Horses transmit the disease by coughing or sneezing on another horse. Horse caregivers could spread it by touching a diseased horse’s face and then touching another horse. Caretakers and owners of horses at Rancho Sierra Vista have been asked to take precautions such as wearing disposable boots and using foot baths when they go from barn to barn. There is no specific protocol for treatment, but horses, depending on their symptoms, are given IV fluids, anti-viral drugs and anti-inflammatory drugs.

Though the disease is not transmitted over long distances by air, nearby stable managers said they are concerned about the outbreak.

David Provence, who manages the Sycamore Trails equestrian center, said his concern is that before the virus was positively identified, horses had traveled among the stables.

“It’s concerning because it’s potentially fatal,” he said. “It’s as infectious as a cold. most horses have immunity to this because it’s similar to one they are regularly vaccinated for. but if a horse is under physical stress or old, it could catch it.”

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