78 (3) 189-193
This case report describes a small outbreak of neonatal foal death in Belgium due to infection with equinearteritis virus (EAV). The outbreak started with one foal suffering from acute dyspnea four days after birth.Despite intensive treatment, this foal died within a few hours. Three weeks later, another foal was born on thesame farm in a healthy condition, although placental edema was found. At the age of 10 days, the foal showedacute respiratory distress and severe dyspnea and died shortly after. Post-mortem examination of both foalsrevealed consolidated diaphragmatic lung lobes with compensatory emphysema. Histologic lesions consisted ofa mild acute interstitial pneumonia. Microscopic examination of the allantochorion from the second foal showeda focal necrotizing vasculitis, and immunolabeling demonstrated the presence of EAV antigens in chorionicvascular endothelial cells and macrophages. Upon inoculation of rabbit kidney (RK13) cell culture with asuspension of lung tissue, a cytopathic effect was observed. The agent was identified as equine arteritis virus bymeans of immunostainings.