An outbreak of equine herpesvirus (EHV-1) at New Jersey’s Monmouth Park in late October resulted in the state-ordered quarantine of more than 1,000 horses at that facility on Oct. 26, 2006, with horses that went to The Meadowlands after Monmouth Park closed also quarantined. (The Mid-Atlantic Veterinary Clinic in Ringoes, New Jersey was also put under a related quarantine Nov. 1, 2006.)
After receiving word of the outbreak, the Maryland Jockey Club joined Delaware Park, Philadelphia Park and Penn National in closing its stable gates to horses based in New Jersey. Horses stabled at Monmouth Park or The Meadowlands were not allowed to enter the Laurel Park, Pimlico or Bowie Training Center stable areas.
The Laurel Park racing office stopped taking entries on horses that raced at The Meadowlands after Oct. 14, 2006; nor did it accept entries from any trainer stabled at a farm or training center that may have run a horse at The Meadowlands.
On Nov. 7, 2006, the MJC revised its ban to prohibit entries from any farm or training center if a horse from that facility had raced at The Meadowlands since Oct. 24, 2006. Horses that raced at The Meadowlands prior to Oct. 24, 2006 will now be accepted at Maryland racing facilities. However, MJC officials said that until further notice, they will continue to prohibit horses stabled at Monmouth Park from entering Maryland tracks.
Equine herpesvirus can cause upper respiratory infection and fever and can also cause mares in foal to abort. But in its dangerous neurologic form, it attacks the nervous system and can lead to paralysis or death. As there is currently no known method to reliably prevent this form, which resulted in the deaths of six Maryland horses last year, containment is crucial while the virus it runs its course.