"Equine herpes is a term that refers to any one of several highly contagious diseases in horses, which may occur as a result of infection by either of two closely related herpes virus, equine herpesvirus-1 and equine herpesvirus -4 (EHV-1 and EHV-4). Both EHV-1 and EHV-4 are worldwide in distribution and constitute a health risk for domestic horses of all ages. Infection with either EHV-1 or EHV-4 is characterized by respiratory tract disease. Severity of clinical signs varies depending on age and general health of the infected horse. EHV-1 is also often referred to as “Equine Rhinopneumonitis”."
Dit heb ik van het internet gehaald. Er is heel veel over te vinden. Kort gezegd is EHV-1 de aggressievere variant, veroorzaakt vaak spontane abortus etc. o.a. hierom is er meer onderzoek naar gedaan dan naar EHV-4. Probeer eens een zoekmachine op "equine herpes" EHV-1 EHV-4