Equine Herpesvirus (EHV-1) Outbreak

Horses February 24, 2016 Print Friendly and PDF
Image:EHV-feature-image.jpgFind out more about the recent Equine Herpesvirus (EHV-1) outbreak and access links to recent reports and resources.



EHV-1 Outbreak Information

EHV-1 Outbreak

What is EHV-1?

  • Equine Herpes Virus is one of the most common respiratory diseases affecting horses. There are at least four equine herpes viruses.
  • EHV1 and EHV4 are the two herpes viruses that commonly cause respiratory disease.
  • EVH1 can also cause neurologic disease.
  • EHV-1 is commonly found in horse populations worldwide and was previously referred to as the equine abortion virus. Although EHV-1 is well known for causing reproductive disease, it is also known to cause respiratory and neurological disease.
  • Transmission occurs when infected and uninfected horses come in either direct (nose to nose contact) or indirect (through buckets, clothing, blankets that are contaminated) contact with nasal discharges of infected horses. The virus can travel via aerosol (in the air) for short distances.
  • In horses infected with the neurologic strain of EHV-1, clinical signs may include: nasal discharge, incoordination, hind end weakness, recumbency, lethargy, urine dribbling and diminished tail tone.


For the most up-to-date information on the EHV-1 outbreak, follow eXtension Horses on Facebook and Twitter.


Want to learn more about EHV-1? View the EHV-1 Webinar in the link below:


2015 EHV-1 Suspected Cases & Information


EHV-1 Outbreak Tracker Maps



Extension Resources and Publications on EHV-1

Informational publication written by Dr. Kerry A. Rood, Utah Extension Veterinarian and Dr. L. Earl Rogers, Utah State Veterinarian. Read more about the background, clinical signs, diagnosis and prevention of Neurologic Equine Herpes Virus (EHV-1).
Informational articles and resources about EHV, provided by the Colorado State University Extension.
Informational fact sheet written by Jenifer Nadeau, Associate Professor and Equine Extension Specialist at the University of Connecticut. This fact sheet touches on the different types of equine herpesvirus, clinical signs, routes of transmission and how to protect your horses from EHV.

Biosecurity Information/Resources for Horse Farms

Learn about evaluation methods and advice for prevention, protection, and proactive ways of minimizing disease risk in your horse facility by watching this recorded webcast, hosted by Dr. Betsy Greene, Professor of Animal Science and Extension Equine Specialist at the University of Vermont.
The United States Department of Agriculture has provided this brochure with general suggestions and guidelines regarding biosecurity on horse farms, including topics on transporting horses and using disinfectants.

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This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.