The Equine Expert

Equine Herpes Virus (EHV) – What you need to know about the virus and how to protect your horses
By Tanja Schnuderl

(click image to view larger)

Whether you take care of your horses at home, or if you are a barn manger like me and other people trust you with the wellbeing of their horses: Here is what you need to know about EHV and how to protect your horses.

As of March 1st, 2021, the FEI has cancelled all international events in 10 countries on the European mainland, effective immediately until 28 March 2021 due to the rapid progression of a very aggressive strain of the neurological form of Equine Herpes Virus (EHV-1).

The virus:

Equine Herpes Virus (EHV) is a contagious equine disease and certain strains of the virus can cause severe illness in horses. There are nine strains of the virus, however, EHV-1, EHV-3 and EHV-4 are the most serious health risk for domestic horses. Affected horses may suffer from respiratory disease and abortion in pregnant mares. Young foals are also at risk and can die from the infection. Other horses suffer from neurological disease, which is more dangerous. It is currently unknown, what causes some infected horses to develop the serious neurological form (Equine Herpes Virus Myeloencephalopathy, EHM) that can be fatal.

While there are several vaccines available for protection against both respiratory disease and abortion, at this time there is no licensed vaccine that protects against the neurologic disease (EHM). However, EHV vaccines do reduce the clinical signs and shedding of the virus.

How is it being transmitted?

EHV can be transferred through the air from horse to horse up to distances of 5 meters/16 feet.  An infected horse can transmit the virus to other horses through nose-to-nose contact and coughing. The virus can also be transmitted via shared equipment (tack, feed and water buckets) or via clothing/hands of people who have handled the infected horse (e.g., horse owner, barn manager, boarders, stall cleaners, etc.).

Symptoms of an infected horse:

  • Nasal discharge (snotty nose) and coughing
  • Fever
  • Depression / loss of appetite
  • Loss of bladder function (urine dribbling)
  • Hind limb paralysis (Not being able to rise / leaning against a wall or fence for balance

What to do:

If your horse develops fever, respiratory signs or neurological signs, or potentially has been exposed to the infectious agent, immediately notify your veterinarian.

  • Isolate the horse (in a paddock/stall without any contact to other horses).
  • Wash and disinfect your hands and change your clothes and shoes.
  • Make a list of all horses that were exposed to the potential infected horse. To discuss with your vet if they if they should be isolated as well.
  • Clean all equipment and horse housing areas of the infected horse. Always wash and rinse surfaces when possible prior to applying disinfectants. Cleaning first allows for removal or organic material which makes the disinfectants more effective. After cleaning the surface, follow with a disinfection process. The virus is easily killed in the environment by most disinfectants.
  • Take and record the horse’s temperature 2x daily.

If the horse is found to be shedding EHV-1, the level of risk to other horses increases significantly. Be prepared to implement disease control and quarantine procedures.

Find more information on contagious equine diseases and how to practice biosecurity: Contagious equine diseases - Minimize the risk and keep your horses safe!

Tanja Schnuderl is a team member with The Equine Expert LLC, a multi-discipline equine expert witness and consulting firm with expert equestrians offering legal expert witness and consulting services in court cases and legal matters. Tanja is an expert on Barn Management and Horse Behavior. She is the Barn Manager for Moon Rising Farm just outside Washington DC and Principal of Sigma Equine LLC, an equine appraisal business. Tanja grew up in Germany and was a paralegal for many years. For more information on Tanja Schnuderl email,


The Equine Expert. All rights reserved. Site proudly designed and hosted by Big Sky Internet Design