Ribavirin efficiently suppresses porcine nidovirus replication

► Ribavirin effectively inhibited porcine nidovirus infection in a dose-dependent manner. ► Ribavirin affected post-entry steps of the replication cycle of PRRSV and PEDV. ► GTP depletion may be essential for the ribavirin activity against porcine nidoviruses. ► Ribavirin did not trigger catastrophic mutations in the nidoviral genome. ► Treatment of ribavirin could be a good antiviral therapy against porcine nidoviruses.