Following a state order, Virginia Tech's Marion duPont Scott Equine Medical Center at Morven Park in Leesburg has been under quarantine since Tuesday, Feb. 20, due to the suspicion that some horses were infected with the neurological form of equine herpesvirus (EHV-1).
"Four horses total have shown neurological signs," Dr. Nathanial A. White II, the Jean Ellen Shehan professor and director of the equine center, said. "The horses are all stable and we have had no deaths."
EHV-1 is one of several strains of the equine herpesvirus, a highly contagious disease that can cause respiratory signs, prenatal infection, abortion and inflammation of the brain. This strain of herpesvirus is not transmissible to humans, but can be transferred between horses through nasal fluids and bodily secretions. Symptoms of the virus include fever, coughing, nasal discharge, loss of balance and recumbency or lying down.
ON FEB. 7 a horse that had been brought to the hospital for an unrelated emergency developed a fever and symptoms of the nervous disease, White said. The horse was immediately isolated, the doctor said, and tested positive for EHV-1 Feb. 16.
The morning of Feb. 20 two more horses at the veterinary hospital began to show neurological symptoms, leading the Virginia Department of Agriculture and Consumer Services to order the quarantine.
"So far we have two confirmed positive cases," White said. "All of the horses have been placed in isolation."
BY FRIDAY, Feb. 23, the Virginia Department of Agriculture and Consumer Services took precautionary measures and quarantined additional farms in Virginia. Six different premises with a total of 72 horses in Loudoun County have come under quarantine.
"We are being very conservative in our approach and are quarantining farms that have horses on the premises that were at the equine center during the possible contagious period," Dr. Richard Wilkes, a Virginia State Veterinarian, said at the time of the announcement. "The quarantines are precautionary measures and do not mean there are sick horses on the premises."
The quarantine at the equine center is expected to last anywhere from 14 to 28 days. During the time of the quarantine, no horses will be allowed to leave or enter the hospital.
"We are following the most stringent procedures possible in order to protect the horses in our care as well as the general equine population," White said.
White would not reveal the number of horses under care at the veterinarian hospital or the types of horses infected, but said that the center has been in contact with the owners of all of the animals.
THE MORVEN PARK Equestrian Center imposed a 21-day voluntary quarantine beginning Wednesday, Feb. 21, because of its close proximity to the veterinarian hospital and to ensure the safety of all horses that visit the center for public events.
"We feel it is the responsible thing to do in the horse community," Charles Muldoon, director of development for the equestrian center, said. "If we were doing one of our events, lots of horses would be coming into contact with each other."
While Muldoon said the equestrian center has a few horses housed on the property, he said it was important to err on the side of caution.
"None of these horses have left the property, but we want to make sure everything is safe so future horses who come to us are safe," he said.
The Loudoun Therapeutic Riding Foundation is located at Morven Park and its horses are some of the ones housed at the center. However, Muldoon said, they are not currently in session so the quarantine will not impact the foundation's ability to operate.
WHITE SAID THAT up to 70 percent of horses can carry the virus in their system without showing any symptoms.
"When the animals are stressed or something else happens to them, it can stimulate the virus," he said. White added that the disease is difficult to eliminate because of its dormant nature.
"Most of the treatment is symptomatic treatment, until the virus runs its course," he said. "But this [neurological] form is actually rare in horses. It can actually be fatal."
Dr. Martin Furr, one of the internists at the equine center, is an expert on the disease, White said.
"The state will be informed of all actions we take," he said, "but we are very fortunate to have care we need right here."
Veterinarians at the center have be working closely with the state veterinarians and have been on conference calls with the Department of Agriculture and Consumer Services every day.
"I applaud the state for taking control of the situation and getting a handle on it," Muldoon said. "They were very proactive. And the horse community is really wrapping its arms around this in a positive way."