How Can I Protect My Horse From Equine Herpes Virus (EHV-1)

EHV-1 is a rhinopneumonitis that usually causes respiratory infection in horses. Infected horses will often exhibit symptoms such as: high fevers, lethargy, nasal discharge, enlarged lymph nodes and swelling of the throat latch area. Occasionally, EHV-1 may cause swelling (edema) of the limbs and can also lead to your horse developing bacterial bronchitis or pneumonia. Currently, the strain of EHV-1 that has been spreading in the latest outbreak is a more severe version.

Why Should I Be Concerned About Rhinovirus?

Unfortunately, EHV-1 can also cause late term abortions, foal deaths and neurological problems. The latest, aggressive strain of EHV-1 is called Equine Herpesvirus Myeloencephalopathy (EHM) and is associated with neurological symptoms. It can severely affect the brain and spinal cord causing hind end weakness, lack of coordination (ataxia), leaking of urine or the inability to pass urine or manure. The end result for horses infected with the EHM strain is paralysis and often death. [1]

How Can My Horse Get EHV-1?

EHV-1 or EHM is a highly contagious virus and is typically spread by direct, horse-to-horse contact. The virus is shed in the respiratory tract of infected horses meaning it is spread through the nasal discharge including coughing and sneezing. It is possible to spread it indirectly through contact with contaminated items such as shared buckets, trailers, tack, people’s hands and grooming equipment. [2]

Ways to Help Keep Your Horse From Contracting the Neurologic Strain of EHV-1

Dr. Kim A. Spraybery, D.V.M., a board-certified medicine specialist, shared several strategies to minimize your horse’s exposure to the rhinovirus. Her recommendations are for at your home barn as well as during traveling, stabling elsewhere and in situations where avoiding other horses is impossible such as at shows. While these are not guaranteed to provide 100% protection, the effort to restrict your horse’s exposure may minimize the risk of contracting EHM as outbreaks are occurring stateside and internationally. [3]

  • Maintain your horse’s vaccination schedule
  • Limit exposure to other horses
  • Prevent nose-to-nose contact especially at shows
  • Skip the community water troughs
  • Don’t share buckets, feed scoops, grooming equipment or tack
  • Don’t pet or interact with other equines
  • Don’t allow others to pet or interact with your horse or horses
  • Keep your hands washed
  • Disinfect your trailer immediately after use
  • Disinfect stalls at the showgrounds before stabling your own horse
  • When shipping, verify that boxes are disinfected between shipments
  • Quarantine any new arrivals at your farm for 14-21 days [3]

Supplementing Vitamin E Can Improve Immunity

Research has shown that domestic animals that are fed additional vitamin E have a stronger immune system. According to The Horse Magazine, horses fed diets fortified with vitamin E have shown “increased specific infection-fighting white blood cells’ bacterial killing capacities.” Vitamin E can also help equine’s in stressful situations remain healthy and maintain their immunity. [4]

As outbreaks of rhino viruses have been reported in Florida, Connecticut and California as well as across the globe, increasing the nutritional support your horse receives may help prevent infection or assist in recovery.  Feeding nutritional supplements, including Vitamin E, that support gut health also boost the equine immune system making your horses better able fight off infections, including EHV-1 and EHM. [5]

TWYDIL® S May Help Protect Your Horse During the EHV/EHM Outbreak

While supplements alone may not prevent illness, a digestive health supplement can help boost the immune system. Research has shown that a strong immune system begins with improving the health of the digestive system. [6] Used daily, TWYDIL® S paste improves your horse’s gut flora thereby restoring his digestive health as well as his overall health. As our unique formula is continually fed, the Vitamin E, healthy fats, prebiotics and antioxidants make your horse’s body better able to fight off infection and increases the chances of a full recovery following serious illness. [6]

FEI is maintaining a database for the current EHV-1/EHM outbreaks in the US and abroad. Get the latest information and statistics at


  1. Young, Amy. “Equine Herpesvirus 1 (EHV-1), Equine Herpesvirus Myeloencephalopathy (EHM).” School of Veterinary Medicine, July 31, 2019. Web. Retrieved April 1, 2021 from
  2. “FAQ: Equine Herpesvirus (EHV).” AAEP – American Association of Equine Practitioners. 2020. Web. Retrieved April 1, 2021 from
  3. Spaybery, Kim A, DVM. “What are the Symptoms of EHV-1 and how do I protect my horse?”. Hagyard Equine Medical Institute. Web. Retrieved from
  4. Oke, Stacy, DVM, MSC. “Vitamin E Might Provide Support For Horses in Stressful Situations.” The Horse – Your Guide to Equine Health Care. Sept. 17, 2020. Web. Retrieved April 1, 2021 from
  5. Henneman, Kimberly, DVM, DACVSMR (EQ, K9), FAAVA, DABT, CVA, CVC. “An integrative approach to Equine Herpes Myeloencephalopathy (EHM).” Innovative Veterinary Care. August 14, 2017. Web. Retrieved April 1, 2021 from
  6. Gill, Amy. “Building Blocks to a Healthy Immune System.” Holistic Horse. Web. Retrieved April 1, 2021 from