The New Jersey Department of Agriculture (NJDA) has quarantined a property in Burlington County after a horse developed the highly infectious equine herpes myeloencephalopathy (EHM).
The animal, a 17-year-old warmblood gelding, developed acute clinical signs on April 1, and is currently undergoing hospitalization. EHM is the often-deadly neurologic form of Equine Herpes Virus (EHV-1) infection. The 26 remaining horses on the premises are under quarantine and being monitored for sickness.
No recent horse movement has occurred in the herd, making the risk of disease spread from the case very low. There are no known connections between this EHM case and the first county case earlier this year in January.
“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 properties and puts in place preventive measures to contain the virus,” New Jersey Secretary of Agriculture Ed Wengryn said.
“Horse owners are encouraged to work with their veterinarian and the state when animals show symptoms such as those of EHV-1.”
The EHV-1 organism spreads quickly from horse to horse and can cause respiratory problems, especially in young horses, and spontaneous abortions in pregnant mares. It neurologic form can result in death. The incubation period of EHV-1 is typically two to 10 days. Clinical signs include respiratory disease, fever, nasal discharge, depression, cough, lack of appetite, and/or enlarged lymph nodes.
In horses infected with the neurologic strain of EHV-1, clinical signs typically include mild incoordination, hind end weakness/paralysis, loss of bladder and tail function, and loss of sensation to the skin in the hind end. The virus spreads readily through direct contact with infected materials.
The NJDA Animal Health Diagnostic Laboratory is available to assist veterinarians with the EHV-1 testing. For contact information, visit the lab website at www.jerseyvetlab.nj.gov. Concerned owners should consult with their veterinarian prior to taking any action, as the clinical signs of infection with the neurological form of EHM are common to many other diseases.
EHM is a reportable disease in the state. If a horse is exhibiting neurologic signs or is suspected of having equine herpes, owners should call their veterinarian immediately.

