On March 28, 2007, a horse housed in a private stable in Rome, Me., was diagnosed with the neurologic form of equine herpesvirus-1 (EHV-1). The 3-year-old gelding had been euthanatized on March 19, 2007, after exhibiting severe neurologic signs over a 24-hour period. A 17-year-old horse at the same location had died of similar signs one day earlier. According to the State Veterinarian, Don Hoenig, VMD, this is the first reported case of the neurologic form of EHV-1 in Maine.

Additionally, an 8-year-old horse in Wales, previously housed for a short time at the stable in Rome, is currently under treatment for neurologic signs consistent with EHV-1. The Department of Agriculture has placed both stables under quarantine.

EHV-1 is primarily a respiratory pathogen in horses which can cause respiratory illness and abortion, but it can also cause a paralytic neurologic disease. The virus is contagious and can be spread by direct contact with infected horses, respiratory secretions, and contact with contaminated objects, such as feed and water buckets and other barn tools and tack. Following initial exposure, EHV-1 has the ability to develop into an inapparent latent infection which can provide a reservoir of virus for continual transmission.  

Over the past two years, the Department of Agriculture, in consultation with equine veterinarians and representatives from the equine industry, including racetrack officials, has strongly recommended that racetracks, agricultural fairs, and equine training facilities in Maine require that horses entering their facilities be vaccinated for EHV-1 not more than six months or less than 14 days before entry. Department animal health officials are also encouraging all horse owners to consult with their practicing veterinarian on recommendations concerning vaccination and monitoring for the disease.

For detailed information, please consult the U.S. Department of Agriculture’s Web site at www.aphis.usda.gov/vs/nahss/equine/ehv/

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.