February 2008 
by Nanci T. Steveson

On January 21, Dr. Carol Swanby, a private veterinarian for trainer Rob Bailes who stables 19 horses at the Bowie Training Center, noticed something suspicious in one of his horses. As of press time it is unclear exactly what the initial symptoms were that alerted Dr. Swanby to a possible herpes infection, but she was not going to take any chances. The horse was immediately moved to an isolated barn and all the horses in Barn #7 at the training center were confined to their shed row.

On January 22 the Maryland Department of Agriculture (MDA) imposed an “Investigational Animal Hold Order” on Barn #7, which officially restricted the movement of the horses housed there in or out of the barn until the results of blood tests and nasal swabs from the symptomatic horse came back.

Vice President of Communications for the MD Jockey Club, Mike Gathagan, said they wanted to take a proactive approach to the possibility of an infection. “Some other race tracks have tried to hide the virus, but that isn’t how we want it done.” The horse in question has shown no further neurologic symptoms. Test results on blood samples came back negative on January 24 and nasal swab results were also negative as of January 25.

The MDA field veterinarian handling the case inspected the barn that morning and reported no signs of the virus in any of the horses housed there. At that time, the hold order on Barn #7 was lifted by the MDA. Maryland Jockey Club president and general manager Chris Dragone was very “pleased that the system worked and that everybody worked together so well.”

Is this close call a sign that herpes has moved back into MD? More importantly, if so, what does that mean to us as a community?
Dr. Mike Erskine of Damascus Equine Associates and President of the Maryland Horse Council said his overall sense is that “infectious and contagious diseases in horses are going to be an issue that horse people will have to deal with,” but for each incident that occurs there is a definite improvement in the response by the officials and the community at large.

“The more information that gets out,” Dr. Erskine continued, “and the more people are educated in how to respond to these situations, the more they trust the process and have confidence in how to handle it. With each occurrence, the procedures used to protect the rest of the community are improved and become more effective. The sharing of information between stables, and between officials, is very important and beneficial to our understanding of how to combat this disease.”

EHV-1 is an airborne virus that is contagious up to 35 feet. However, not all horses actively shedding the virus will show symptoms. Although there is no vaccine that is effective against the neurological form of EHV-1, a good vaccination program may lessen the severity of an outbreak.

More information about EHV-1 and recommended bio-security measures can be found at www.mda.state.md.us and click on “Equine Herpesvirus Status and Prevention Measures under Hot Topics