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