New Jersey Department of Agriculture MEMO: EHV-1 Positive Horse in Hunterdon County

A Somerset County premises and a Hunterdon County veterinary hospital were placed under quarantine after a horse tested positive for equine herpes myeloencephalopathy (EHM) caused by equine herpesvirus-1 (EHV-1).  The index horse is currently in isolation at the hospital and both the index farm and the hospital have been placed under quarantine. The horse’s rapid progression of neurological signs is typical for EHV-1. Horses that have been exposed to the index horse are being moved to a remote facility, which will also be placed under quarantine. This will allow the veterinary hospital to clean and disinfect and reopen to allow for continuity of business. Immediate biosecurity measures are in effect and will be in place for the duration of the quarantine. Additionally, all the horses will be temperature checked twice a day in order to confirm the virus is not spreading. To date, there are no other sick horses on either premises.

EHV-1 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.  Transmission of the virus is mostly via direct contact with infected materials, therefore, tack must not be shared between horses and biosecurity measures must be utilized.  While highly infectious, the virus does not persist in the environment and is neutralized by hand soap, alcohol-based hand sanitizers, and sunlight.

EHM is a reportable disease in New Jersey and must be reported to the Division of Animal Health at 609-671-6400.  The New Jersey Animal Health Diagnostic Laboratory (609-406-6999) recommends PCR testing for horses exhibiting neurological signs.

EHV-1 Neurologic PCR ($50.00)Whole blood PTT/Nasal swab, brain tissue

Sick horses: Whole blood (purple top tube) & nasal swab

Dead horses: brain tissue, spinal fluid

EHV-1 SN titer ($15.00)1 ml serum, w/cold pack 2-4 days

Contact Dr. Amar Patil (609) 406-6999 or via email at

Laboratory specimen(s), along with a laboratory submission form, may be sent to:

(If sent via courier service):NJ Department of Agriculture
Animal Health Diagnostic Laboratory
NJPHEAL, 3 Schwarzkopf Drive
Ewing, NJ 08628
(If sent via U.S. Postal Service):NJ Department of Agriculture
Animal Health Diagnostic Laboratory
P.O. Box 330
Trenton, NJ 08625