08/08/2025
🦠 A recent case of the highly infectious equine herpes myeloencephalopathy (EHM) has been confirmed in Sussex County, NJ. Per the NJ Dept of Ag, a 20-year-old mare developed acute clinical signs on August 03, 2025, and was subsequently humanely euthanized. One week prior, another horse on the property presented with similar neurological signs and was humanely euthanized, without diagnostic testing. The property is quarantined.
📖 What is EHV-1?
Equine Herpes Virus type-1 (EHV-1) is a virus that causes respiratory disease, abortion, neonatal death, and neurologic disease. EHV can cause Equine Herpesvirus Myeloencephalopathy (EHM), the neurologic form of herpes.
🤧How is it spread?
EHV-1 is primarily spread by direct horse-to-horse contact by respiratory secretions. However, indirect contact with contaminated equipment and personnel can spread the virus. Following infection, horses may become latent carriers and the virus may be reactivated after stress such as travel and exercise, or high doses of corticosteroids. The incubation period ranges from two to 10 days.
🩺What are the symptoms of EHV-1?
Common symptoms include fever, coughing, lethargy, nasal discharge, and inappetance. Symptoms of the neurologic form include ataxia (incoordination), weakness, difficulty standing, recumbency, loss of tail tone, and difficulty urinating.
😷How can you protect your horse?
While vaccination can decrease clinical signs and shedding, it does not protect against the neurologic strain.
While at a show, avoid nose-to-nose contact with horses from other barns, and don’t share equipment such as buckets, wheelbarrows, and pitchforks. Wash your hands frequently, and take extra precautions if working with multiple groups of horses.
🌡️ Consider taking your horse's temperature twice a day when traveling. Temperatures greater than 101.5 or any signs of illness should be reported to your veterinarian immediately.
🧬How is EHV-1 diagnosed?
The virus is detected in nasal swabs and blood samples by PCR testing. At Rhinebeck Equine, we offer in-house rapid EHV-1 PCR testing on nasal swabs. Results are available in ~60 minutes.
