An Outbreak of Equine Herpesvirus-4 in an Ecological Donkey Milk Farm in Romania

Equine herpesviruses are important pathogens causing significant economic loss in equine and asinine populations. EHV-1/4 strains are mainly associated with respiratory distress. The aim of this study is to report the first EHV 4-associated respiratory disease in donkeys in Romania. Thirty-seven of three hundred jennies in an ecological donkey farm in southwest Romania started initially showing signs of severe upper respiratory tract disease, with ten concomitant late abortions/neonatal deaths and three neurological cases. There were nine fatalities. Pathological examination was performed, and samples were collected for Real-Time PCR analysis and histology. In addition, serum samples from 28 individuals with respiratory symptoms were collected and tested using indirect ELISA. RT-PCR identified the EHV-4 strain. Acute, diffuse necrotizing bronchointerstitial pneumonia with occasional intraepithelial intranuclear viral inclusion bodies was identified. Additionally, EHV-1/4-specific antibodies were found in 15 of the 28 sampled animals. Few studies on donkeys and herpesviruses have been published, and this is the first reported case of EHV-4 outbreak in Romania. There is a need for more extensive seroprevalence studies as, currently, the status of EHV-4 infection in donkeys in Romania is unknown.