Pathogenesis of ovine pseudorabies (Aujeszky's disease) following intratracheal inoculation.

Pseudorabies virus was inoculated intratracheally into sheep to investigate the pathogenesis of pseudorabies virus infection. Clinical signs of pyrexia, depression, frequent swallowing, facial fasciculations, chorea, excessive salivation, mild tympanites, labored breathing and focal pruritus were followed by death Macroscopic lesions were severe focal facial trauma, petechiae in cervicothoracic ganglia and dilated esophaguses. The medulla oblongata and the trigeminal, cranial cervical, cervicothoracic and parabronchial ganglia contained pseudorabies virus and pronounced nonsuppurative inflammatory changes. The neural distribution of lesions and virus suggests that the virus travelled from the respiratory mucosa to the central and sympathetic nervous system by two routes: 1) in the vagus and glossopharyngeal nerves to the medulla oblongata and 2) in the postganglionic fibers to the sympathetic ganglia. The presence of virus in the nasal mucus indicated that horizontal transmission of pseudorabies virus may occur among sheep.