Equine Herpesvirus (EHV): Symptoms, Prevention & How to Protect Your Horse

Understanding Equine Herpesvirus (EHV-1 & EHV-4)

Following the recent confirmation of equine herpesvirus type 1 (EHV-1) in a horse with neurological disease at the Irish Equine Centre, it is timely to revisit what this virus is, how it spreads, and how to reduce your horse’s risk.

Equine herpesvirus (EHV) is a common and highly contagious viral infection in horses. It can cause a range of issues, from mild respiratory disease to more serious complications such as abortion and neurological disease.

The two most important strains are:
•    EHV-4 – primarily causes respiratory disease, especially in young horses
•    EHV-1 – more severe; associated with abortion, neurological disease and, in rare cases, death

How EHV Spreads Between Horses

One of the biggest challenges with EHV is that it can remain latent (dormant) in the horse’s body and reactivate during periods of stress such as travel, illness or changes in management. Horses can then shed the virus without showing obvious signs, making it difficult to control.

EHV spreads easily through:
•    Nose-to-nose contact (respiratory route)
•    Contaminated equipment, clothing or surfaces
•    Contact with aborted material

The virus can survive in the environment for several days, increasing the risk in busy yards.

Clinical Signs of EHV in Horses

Signs typically appear within 2–10 days of infection and may include:
•    Fever
•    Lethargy and reduced appetite
•    Nasal discharge and coughing

In more severe cases (particularly EHV-1):
•    Weakness or incoordination
•    Paralysis
•    Abortion in late pregnancy

If any of these signs are observed, veterinary advice should be sought immediately.

Diagnosis and Treatment

EHV cannot be diagnosed based on clinical signs alone. Confirmation requires veterinary testing, usually via nasal swabs or blood samples.

There is no specific cure, so treatment focuses on supportive care:
•    Managing fever
•    Maintaining hydration
•    Preventing secondary infections

Rest is essential, and horses should return to work gradually after recovery.

Prevention: Reducing the Risk of EHV

Good management and biosecurity are key to controlling EHV:
•    Isolate new arrivals
•    Minimise stress (transport, training changes)
•    Separate affected horses during outbreaks
•    Maintain strict hygiene (equipment, clothing, handlers)
•    Consider vaccination, particularly for breeding stock
•    Support immunity through nutrition

Supporting your horse’s immune system through balanced nutrition plays an important role in reducing the risk and severity of EHV.

A diet that provides adequate vitamins, minerals and amino acids supports overall health and resilience. As over 70% of the immune system is linked to gut health, maintaining a healthy gut microbiome is essential.

Targeted supplementation can help support both gut and respiratory health. Plusvital Betapulmin is formulated to optimise immunity and respiratory function, containing high levels of yeast-derived 1,3–1,6 beta-glucans along with antioxidant vitamins C and E.
Equine herpesvirus is widespread and can be serious, but with good management, biosecurity and nutritional support, the risk can be significantly reduced and effectively controlled.

Ask your vet about Betapulmin today.