Horses on Lockdown Following Virus Outbreak

This story originally appeared on Half Moon Bay Patch on May 18, 2011.

Story and photos by Kristine A. Wong

Ranch owners along the Coastside have quarantined their horses following news that 800 horses from several Western states were likely exposed to a neurological form of equine herpes virus (EHV-1) at the National Cutting Horse Association’s Western National Championships in Ogden, Utah.

The outbreak has spread to several of those states, including California, which currently has 10 infected horses in Napa (one horse), Kern (two), Placer (two), Stanislaus (four) and Amador (one) counties, according to the California Department of Food and Agriculture (CDFA).

All 10 horses attended the competition held in Ogden from April 29-May 8, and one horse showing signs of the virus was euthanized in Bakersfield on Friday, according to CDFA. Two horses are currently being treated at UC Davis.

“We haven’t seen any cases in San Mateo County at this time,” said Tina Mastrangelo on Wednesday afternoon. Mastrangelo works at Bayhill Equine, a veterinary practice in Redwood City.

Despite the lack of cases in the county, Robin Camozzi, who manages four horse ranches for the Half Moon Bay Feed and Fuel store, said she wasn’t taking any chances. “I’ve put all our ranches on a 14-day—no one in or out—quarantine,” she said. “We do not have any horses on any of our ranches that have been out or gone to any shows where they would have been exposed, and I want to keep it that way,” she said.

In Montara, Deborah Titone locked down Renegade Ranch on Wednesday afternoon by placing hand-painted signs reading “Due to EHV-1 – Access Closed Till 6-10” along both entrances of the Moss Beach/Montara trail that runs through her property. The trail is frequently used by horses from neighboring ranches on their way north to Montara Mountain or south to Moss Beach.

“Our horses are being quarantined for three weeks,” Titone said, who both boards and breeds horses at her ranch. “No new horses are being allowed to come in, either,” she said. Like Camozzi, Titone said she would wait and see what happens with the virus before deciding what to do at the end of the quarantine.

Though Titone first heard about the outbreak on Monday, she wasn’t concerned until she heard that a case had been confirmed in Napa on Wednesday morning. The fact that a horse in the Bay Area had been hit, she said, was what prompted her to lock down the ranch later that afternoon.

Ranch owners and managers say there is no cause for panic, but that they are concerned because the particular form of the virus is airborne and has caused Equine Herpes Myeloencephalopathy in infected horses, a neurological condition which cannot be prevented by vaccine, according to equine specialists at UC Davis.

“It’s spread by being in direct close contact with each other—horses that are nose to nose or who are within the same air space,” said Dr. Gary Magdesian, a critical care specialist at the Center for Equine Health and the UC Davis School of Veterinary Medicine. Magdesian also said that the virus could be spread through shared items such as water buckets, towels, tacks (which have bits that are held in horses’ mouths) and human hands that have contact with an infected horse’s nose and then make contact with the nose of another horse.

Magdesian said that he considers this outbreak to be one of the worst in the last 20 years, due to its national scope, but added that not all horses exposed to the EHV-1 virus get sick. “It’s just like humans who might be exposed to colds or flu in an airplane,” he said. “Not everyone gets really sick.”

The earliest critical sign of the virus is a significant fever, Magdesian said, which would not show up right away if an infection had occurred. The incubation period for EHV-1, he said, is between two to 10 days. “Some horses also get respiratory signs, nasal discharges, and some have neurological signs such as weakness, incoordination, a limp tail, loss of bladder function, and difficulty getting up,” he said.

“It took six men to drag one of my horses up into a trailer so it could be sent to UC Davis for treatment,” said Kathy Benjamin, a Moss Beach resident and horse boarder at Renegade Ranch. Two of her horses died in 2007 from what she suspected was a form of the virus. Another horse died at Moon Valley Ranch next door around the same time period, said Titone.

Titone said that she, Benjamin and other boarders were being especially cautious after that experience four years ago.

“We believe that the virus came from a horse that came through this trail,” Titone said, pointing out that the two horses that died were housed in an area directly adjacent to the trail running through her ranch. “Moon Valley is about 100 yards from here,” she said, pointing through a sparse set of trees where some of the ranch’s horses are housed.

Earlier that year, four horses at Moss Beach Ranch died as well, Titone said, adding the exact cause of the horses’ death is unknown.

Wednesday afternoon, instructor Renette Rambeau at the Moss Beach Ranch’s Equestrian Center said owner Rich Allen had asked to his boarders to voluntarily keep their horses on the property for a few weeks.

“I think people should be aware, know your horse and not panic,” said Pacifica resident April Faugier at Moss Beach Ranch, as she was getting ready to ride her horse Firecracker at the onsite arena Wednesday afternoon. “I’m just keeping an eye on him,” she said, adding that she comes to the ranch daily to visit.

Moss Beach Ranch owner Rich Allen could not be reached by the time of publication.

For information about EHV-1, click on the PDF document in the media box to the right. For updated information about EHV-1 in California, click here. (Information on EHV-1 was attached alongside the story at the time of publication on the website).

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