Equine Herpes Virus


Diagnosis and Testing for Equine Herpes Virus (EHV)



WADDL Contact:


1. What is EHV?

Equine herpesvirus is a large family of viruses numbered EHV-1, 2, 3, 4, and 5. Not every EHV causes the same, or the same level, of disease. The type of EHV of most concern is EHV-1, which is also a reportable disease. For more information on reportable diseases, you can visit the WSDA at https://agr.wa.gov/departments/animals-livestock-and-pets

2. What Are the Symptoms of EHV?

Equine herpesviruses can cause respiratory symptoms and abortion, but EHV-1 and EHV-4 can cause a neurological disease known as Herpesvirus Myeloencephalopathy (EHM). Some horses can be asymptomatic carriers of EHV and can spread the infection through direct horse-to-horse contact, or by transfer on handlers’ hands, clothing, and equipment.

3. How Can I Protect Against EHV?

The vaccines available for EHV are the best defense we have. Another important way to prevent infection is through proper biosecurity procedures such as quarantine of exposed horses, disinfection of handlers and equipment, and testing. 

4. Where can I find out testing details and submission steps ?

Go to our Web Test Search Tool at: EHV Testing at WADDL

5. Resources for More Information:

American Association of Equine Practitioners (AAEP):


Equine Disease Communication Center (EDCC):


UC Davis Veterinary Medicine Center for Equine Health: