Under the direction of State Veterinarian Richard Wilkes, veterinarians with the Virginia Department of Agriculture and Consumer Services (VDACS) are currently quarantining six farms in Northern Virginia with horses that might have been exposed to a horse infected with the neurologic form of equine herpesvirus-1 (EHV-1). The Maryland Department of Agriculture is working with similarly-exposed animals in that state. The infected horse was treated at the Marion duPont Scott Equine Medical Center in Leesburg, Va., which is also under quarantine.

Quarantines will restrict movement on and off the affected facilities. In addition, veterinarians are urging horse owners to observe strict hygiene control procedures, including a thorough cleaning and disinfecting routine using a proven disinfectant/cleaner, to avoid spreading the disease in the environment.

Equine herpesvirus-1 (also known as rhinopneumonitis virus) is a highly infectious disease that usually affects the respiratory system. Occasionally, the virus can also cause neurologic disease. Transmission likely occurs by inhaling infected droplets or ingesting material contaminated by nasal discharges or aborted fetuses.

Clinical symptoms include a fever of 101.5 or higher (or one or more degrees above the horse’s normal rectal temperature) difficulty urinating, depression, and stumbling or weakness in the hind limbs. Supportive therapy is often successful in treating these cases. In severe cases, horses will be unable to stand; these cases have a very poor prognosis.

For more information on EHV-1, horse owners should check with their veterinarian, contact VDACS’ Division of Animal and Food Industry Services at 804/692-0601, or go to www.aphis.usda.gov/vs/nahss/equine/ehv/ehv_2005.htm.

For more information on EHV-1, check out our free PDF library of EHV-related articles including images, or all our archived EHV-1 articles on TheHorse.com.