Equine Herpesvirus Myeloencephalopathy (EHM)
Update August 16, 2017
Virginia officials confirm a Culpeper horse was euthanized due to the neurologic strain of the equine herpes virus (EHV-1). They have quarantined the horse’s originating farm.
The index horse began exhibiting neurologic signs on August 11 leading to its transport to the Marion duPont Scott Equine Medical Center in Leesburg. Staff isolated the horse and continue its supportive care.
The Virginia Department of Agriculture and Consumer Services’ (VDACS) Animal Health Lab in Warrenton confirmed a diagnosis of the neurologic strain of EHV. It is also known as equine herpesvirus myeloencephalopathy (EHM).
A second horse from the same farm developed a fever and neurologic symptoms leading to its euthanasia Monday. VDACS’ Animal Health Lab confirmed the same diagnosis.
The Virginia Department of Agriculture and Consumer Services states a new horse arrived at the private Culpeper farm 10 days before the first horse’s diagnosis. Additional horses remain, but cannot move on or off the farm for at least 21 days due to the quarantine. The horses’ vaccine histories are unknown by the state.
EHV-1 is highly contagious among horses. It can cause abortion, respiratory and neurologic disease. EHV-1 may lie dormant for long periods of time and then re-activate during a horse’s period of stress resulting in clinical disease.
Veterinarians recommend vaccinating against EHV-1 to help prevent the virus. No current vaccine prevents the neurological manifestation of the infection.
Symptoms may include fever, decreased coordination, nasal discharge, urine dribbling, hind limb weakness, and lethargy.
Veterinarians recommend biosecurity methods when showing or introducing new horses at your farm. These include limiting horse to horse contact and horse to human to horse contact. The virus spreads readily through direct contact with infected materials.
Hand soap, alcohol-based hand sanitizers, and sunlight neutralize the virus.
The Marion duPont Scott Equine Medical Center continues to treat equine patients.