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For Immediate Release: April 4, 2013
Contact: Lynne Richmond 
(609) 633-2954

(TRENTON) – The New Jersey Department of Agriculture has quarantined a Warren County farm after a 22-year-old horse developed the highly infectious equine herpes myeloencephalopathy (EHM).  EHM is the often deadly, neurologic form of Equine Herpes Virus (EHV-1) infection. The horse had not left the premises in years.

The thoroughbred mare was euthanized on March 31 after it had a rapid progression of neurological signs typical of Equine Herpes Myeloencephalopathy and subsequently tested positive for EHV-1.  There are a number of other horses present at the facility, none of which have shown signs of the disease.

This is the third case of EHM in New Jersey this year.  An EHM-positive horse in Somerset County prompted quarantines at two farms in January and two other farms were quarantined in February due to a sick horse in Gloucester County.  No other horses in the two unrelated cases showed signs of the illness and the quarantines were lifted after 21 days of quarantine.

“The Department took swift action to prevent the disease from spreading to other horses by enacting a quarantine, which stops movement of horses in and out of the farm and puts in place preventive measures to contain the virus,” said New Jersey Secretary of Agriculture Douglas H. Fisher

The EHV-1 virus spreads quickly from horse to horse, has a high morbidity and can cause a wide range of symptoms, from a complete lack of clinical signs to respiratory problems, especially in young horses, and spontaneous abortions in pregnant mares.  The neurologic form of EHV-1, additionally, can cause an acute paralytic syndrome, which results in a high mortality. The incubation period of EHV-1 is typically 2 to 10 days.  The virus spreads readily through direct contact with infected materials. While highly infectious, the virus does not persist in the environment and is neutralized by hand soap, alcohol-based hand sanitizers and sunlight.  The virus does not affect humans and other domestic animals, with the exception of llamas and alpacas.

Concerned owners should consult with their veterinarian prior to taking any action as the clinical signs of infection with the neurological form of EHV-1 (EHM) are common to many other diseases. EHM is a reportable disease in New Jersey.  If an owner has a horse that is exhibiting neurologic signs or suspects Equine Herpes, they are directed to call their veterinarian immediately

The NJDA Animal Health Diagnostic Laboratory provides testing for the neurologic form of EHV-1.  For more information, visit or call 609-406-6999.