Equine Rhinopneumonitis

• Causative agent: equine herpesvirus type 1 and type 4
• Primary viral lesions in nasal mucosa and lungs
• Mild, transient bronchointerstitial pneumonia
• Latent infection acting as a reservoir
• Sites of latency: bronchial lymph nodes and trigeminal ganglia
• Replicates in upper respiratory tract epithelium
• Disseminated to lower respiratory tract
• Transported to other organs in T-lymphocytes - viraemia up to 3 weeks
• Vasculitis, abortion
• May be accompanied by secondary bacterial infection