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Equine Herpesvirus Resources

The below resources are provided as a courtesy of the AAEP.  Any resource link below that is not located on AAEP’s website may not have been peer reviewed and are not endorsed by the AAEP; however, these may be valuable resources based on the EHV information provided. If there are additional resources that members of AAEP consider valuable please contact the AAEP office and the recommendation will be taken under consideration.

Equine Herpesvirus Myeloencephalopathy (EHM) & EHV-1 Resources:


Equine Disease Communication Center EHV / EHM Resources: 


Background papers:


Additional Resources:

             o    Managing the risk of EHV-1 infection- A new tool and strategy to prevent EHV-1 disease outbreaks in the U.S. (2019)
             o    Equine Herpesvirus-1 Outbreaks in the U.S.: Regulatory Perspective
             o    Report from EHV-1 Workshop (2014) - Goal of workshop was to develop a consensus document related to EHV-1 regulatory mitigation with the development of an EHM Incident Guidance Document for State Animal Health Officials – with the document to be based on the diagnosis or suspicion of an Equine Herpesvirus Myeloencephalopathy.

Historical Resources Related to EHV Outbreaks:

  • Descriptive Epidemiologic Characteristics of Cases from the 2011 Multistate EHV-1 Outbreak and Summary of Epidemiologic Investigation - One of the largest EHM outbreaks in North America occurred in horses that had attended the National Cutting Horse Association (NCHA) Western National Championship held April 29 to May 8, 2011, in Ogden, UT. Because of the multistate nature of the outbreak, the American Association of Equine Practitioners (AAEP), the American Horse Council (AHC), and the National Assembly of State Animal Health Officials (NASAHO) requested assistance from the USDA–APHIS–VS in coordinating and communicating the outbreak response. It should be noted that the detailed data related to the case characteristics and case premises were not part of the USDA– APHIS–VS reporting during the outbreak. This multistate outbreak provided VS with USDA–APHIS / 2 the opportunity to conduct an epidemiologic investigation of EHM cases and of EHV-1 cases that did not exhibit neurologic signs. This technical report provides a summary of the outbreak investigation with respect to the management of the outbreak. Descriptive characteristics of primary and secondary EHV-1 (with no reported neurologic signs) and EHM cases are included.

  • State and Federal Resources Allocated in Response to the Ogden, Utah EHV-1 Disease Outbreak - From April 29 to May 8, 2011, the National Cutting Horse Association (NCHA) Western National Championship was held in Ogden, Utah. Some horses that attended the event were later diagnosed with EHV-1 infection, and some of these horses developed EHM. The goal of the analysis is to help Federal and State animal health official (SAHO) offices plan for future disease outbreaks by providing an estimate of the resources used to respond to the outbreak

  • EHM: Mitigation Experiences, Lessons Learned, and Future Needs - The objective of this report is to provide information—from interviews conducted with selected scientists and researchers concerning EHV, including EHM, and those involved in mitigation of recent outbreaks or trace-outs related to EHM—that may be useful in mitigating future outbreaks and developing research needs, response plans, and communication materials related to EHM.  Sixteen interviews were conducted relating to 16 disease events—13 outbreaks and 3 trace-outs that occurred between 2004-2007 in the U.S.


International Resources:


Australia Resources:


Canada Resources:

             o Infographic: Equine Herpes Myeloencephalopathy (EHM) - Ontario Animal Health Network (
             o Infographic: Equine herpesvirus-1 abortion - Ontario Animal Health Network (
             o Equine-Owner-EHV-1-fact-sheet-02-14-2017-V2.pdf (
             o Podcast: Broodmare Health - How to manage and reduce the impact of equine herpesvirus-1 abortion in your broodmare herd - Ontario Animal Health Network 

  • Biosecurity resources:

             o National Farm and Facility Level Biosecurity Standard for the Equine Sector - Canadian Food Inspection Agency (
             o National Farm and Facility Level Biosecurity User Guide for the Equine Sector - Animal health - Canadian Food Inspection Agency (
             o Owners and Facility Operators Biosecurity Webinar (Equestrian Canada)
             o Veterinarian Biosecurity Webinar (Equestrian Canada)
             o 2017 Biosecurity Book (
             o Biosecurity-equine-events (
             o Equine On-Farm Biosecurity Risk Assessment (
             o Entry and Exit SOP sample (
             o New Horse SOP sample (
             o Biosecurity, a Road Map to your Horse’s Health (Video)

France Resources:


Ireland Resources:


New Zealand Resources:


United Kingdom Resources: