Mythbuster Monday: Vaccination and EHV-1

On Mythbuster Monday, we tackle a variety of equestrian myths to either bust or confirm. Today’s discussion: Does the EHV vaccine fight against the neurological form of the virus?

It’s Mythbuster Monday, where Horse Nation dives into different equestrian myths and provides research-based evidence to either bust or confirm those myths. Today’s topic: Does the EHV vaccine fight against the neurological form of the virus? What is EHV? What form of the virus does the vaccine prevent? Read further to find out!

Myth: The EHV vaccine fights against the neurological form of the virus

Myth or Fact: Myth


EHV is also known as Equine Herpesvirus or Rhinopneumonitis. This is a family of viruses that are labeled 1 – 5. While many of them don’t cause serious side effects, 1,3, and 4 cause serious harm to domesticated horses. In this article, we’re going to focus on EHV-1, the neurological form of the virus.

Signs and symptoms of EHV-1 include incoordination, hind end weakness, loss of tail tone, lethargy, urine dribbling, head tilt, inability to rise, and leaning against walls to keep balance. EHV-1 manifests with these neurological signs and symptoms, respiratory disease, abortion, and neonatal death.

The disease is contagious and is spread by direct horse-to-horse contact via the respiratory tract from nasal secretions. The virus can also be spread indirectly from contact with physical objects such as human contaminated hands and clothing, contaminated tack, trailers, grooming equipment, feed, and/or water buckets. The virus can survive up to 4 – 6 hours on the mentioned surfaces but can live in manure and soil for up to 30 days.

But, does the EHV vaccine prevent against the neurological form of the disease?


According to an article by UC Davis Veterinary Medicine, no. The vaccines available fight against the respiratory forms of the virus but no vaccine is currently available for the neurological version of the disease.


The American Association for Equine Practitioners (AAEP) also published an article discussing the neurological version of the disease. They write that practicing adequate vaccination protocols will create antibodies against EHV over time. However, presence of the antibodies does not provide immunity against the neurological version of the virus. AAEP states that the best way to prevent spread and contamination of EHV-1 is to practice proper biosecurity measures. They also state that while none of the current vaccines are labeled to prevent the neurological form of the disease, during an outbreak, horses in the area should all get vaccinated to aid in the prevention against the disease through spreading nasal secretions. This is because the vaccine does limit nasal shedding.


Hagyard Equine Medical Institute also published valuable information about EHV-1. Again, they reiterate that there is no vaccine for the neurological form of the virus. However, they write that horses in an exposed area that have not been vaccinated for EHV in the last three months should get vaccinated to reduce the severity of clinical manifestations and to decrease the risk of shedding.


After diving into the research, it’s important to note that horses should be on a regular vaccination schedule to prevent the shedding of the disease. The neurological version of the virus spreads from nose-to-nose contact and by contamination of horse related items. Currently, there is no vaccine on the market that prevents against the neurological form of EHV.

Do you have an equine myth you’d like us to tackle? If so, send it our way! Email your suggestions to [email protected]. Put Mythbuster Monday in your subject line.