Equine Herpes Myeloencephalopathy (EHM)

Equine Herpesvirus Myeloencephalopathy is a neurological disease of horses caused by Equine Herpes Virus (EHV). Equine herpesvirus is a common DNA virus that occurs in horse populations worldwide. The two most common strains are EHV-1, which causes abortion, respiratory disease and neurological disease (any neurological symptoms require calling the State Veterinarian's office at 303-869-9130); and EHV-4, which usually causes respiratory disease only but can occasionally cause abortion and rarely cause neurological disease. EHM can be very contagious, and also can have a mortality (death) rate as high as 30%.

Additional information on EHM

I am a veterinarian:

• CSU paper on EHM
• Awakening the Dormant Dragon: Neurological Form of EHV-1

I am a horse owner:

• A Guide to Understanding the Neurologic Form of EHV Infection
• Keeping Your Horses Safe at Weekend Events
• Rodeo Horses and Respiratory Disease Prevention​
• EDCC Fact Sheet on EHM

I am an equine event organizer or barn owner:

• EHV-1 Biosecurity Guidance for Equine Event Organizers
• Biosecurity for Farm Visits