Equine herpes virus (horses)

About the disease

Equine herpes is not a notifiable disease. Contact your private vet immediately if you suspect disease.

Equine herpes virus (EHV) is a highly contagious airborne disease also known as Equine Rhinopneumonitis. The most common strains are EHV-1 and EHV-4 and can affect horses worldwide.

Both types can cause disease in horses after an incubation period of 2 to 20 days.

Equine Herpes Virus (EHV) on the British Horse Society

Symptoms

Each disease type has strains which may behave slightly differently.

Typical signs of equine herpes include:

• fever of 39 to 40.5 degree Celsius
• upper respiratory tract disease:
• coughing
• nasal discharge
• enlargement of glands under the jaw
• abortion in mares (less common with EHV-4)
• neurological signs (less common with EHV-4):
• lack of coordination
• weakness
• difficulty in urinating and defecating
• inability to stand up

Protect livestock

Management practices have a significant impact on how easily the disease spreads.

Control and prevention will depend on your situation. Methods may include:

• isolation of new horses before introducing them to a group
• hygiene
• vaccination
• testing

Discuss with your private vet before you introduce any new horses.

Recovered animals may remain infected and shed the virus intermittently throughout the rest of their life.

How the disease spreads

Equine herpes virus can be highly contagious. It typically spreads horse to horse over short distances of a few metres. Unlike other viruses spread is unlikely over greater distances.

The disease spreads via:

• inhalation of infected droplets
• ingestion of food contaminated by nasal discharge of infected horses
• sharing water
• contact with objects that have been contaminated. For example, tack, equipment or clothing
• not changing clothes and washing hands in between horses

Equine herpes virus EHV-1

There's currently a Europe-wide alert of increased risk of disease associated with equine herpes virus (EHV-1) which originated in Valencia (Spain). This has already resulted in related outbreaks in other European countries.

The British Showjumping have put in place measures for all horses returning from certain countries in Europe from 1 March 2021. For further information visit management of showjumpers returning to UK from high risk areas of Europe on the British Showjumping.