Equine herpesvirus infectious

Equine herpesvirus types 1 and 4, together with equine influenza virus are, worldwide, the most frequent causative agents of respiratory disease in ho rses. EHV1 can also induce abortion in mares. In spite of a close antigenic relationship, cross reactivity and cross prot ectivity are limited. Seronegative horses in Germany are rare, almost the entire population is in fected. All positive animals can act as potential virus carriers. Thus viru s shredders are a safety hazard to susceptible individuals, particularly th ose with poor immunity due to insufficient vaccination, stress or drugs. The most effective preventative measure is the specific immunoprophylaxis w hich can prevent clinical outbreaks of disease and subsequent economic loss . On the German market monovalent live (EHV1) and bivalent inactivated (EHV 1 and EHV4) vaccines are available. One product contains EHV1 and 4 and inf luenza components. The crucial claim for EHV1 vaccines is equine abortion; for combinations the rhinoneumonitis complex and viral cough claims are mos t important. Vaccination schedules depend on the recommendations of the manufacturer. A stable and complete immune status is only achieved if horses are vaccinated regularly and if the whole population is immunised. The primary course consists of 2 to 3 single injections, booster doses are necessary at intervals of 9 months (EHV1 live) or 6 months (EHV1, EHV4, ina ctivated). The local administration (intranasal, intravaginal) of a EHV1 live vaccine has been proven to be effective under field conditions.