Detection of equine arteritis virus (EAV) in stallions--a contribution to the improvement of EAV diagnosis

Serum samples from 72 stallions were examined for the occurrence of antibodies against equine arteritis virus, of which 41 animals (57%) were found to be positive. 32 of the seropositive stallions were then screened for persistent EAV infection, before and after the breeding season. Semen samples were investigated by RT-PCR followed by dot blot hybridization and nested PCR, and by virus isolation on cell cultures as well. The carrier state was virologically confirmed in 11 of 32 stallions (34%) during the first and in 9 of 20 (45%) during the second investigation. RT-PCR followed by confirmatory methods was more sensitive when compared to virus isolation on cell cultures. It is suggested to implement the national and EU directives by recommending RT-PCR as a routine diagnosis of EAV in semen samples.