Equid alphaherpesvirus 4, also called Equine herpesvirus 4 (EHV-4), is a virus of the family Herpesviridae that cause rhinopneumonitis in horses.

Most infected animals recover in one to three weeks,[3] but death can occur in environments with overcrowding and other stress factors.

Symptoms include fever (38.9–41.7 °C), loss of appetite, and a nasal discharge giving it the nickname "snots".

[4] The Equine Herpesvirus occupies the horse in such a way that allows post infection viral persistency over the lifetime of an animal.

Effective prevention measures, quick diagnosis, therapeutic intervention and the ability to control the spread in the case of an outbreak all allow for the management of EHV.