Distribution of Lesions and Bovine Herpesvirus Type 1 Antigens in Central Nervous System of Cattle Affected by Infectious Bovine Rhinotracheitis

Abstract

Pathological and pathogenic examinations were carried out on three heifers suffering severe respiratory disease on a dairy farm. Extensive fibrinonecrotic inflammation was evident in the respiratory mucosa from the nasal cavity to the lung, nonsuppurative inflammation was found in the trigeminal ganglia, pons and medulla oblongata, and the presence of eosinophilic intranuclear inclusion bodies was detected in the laryngeal glands. Bovine herpesvirus type 1 (BHV-1) antigens and herpesvirus particles were detected in these lesions, and BHV-1 was isolated from the nasal swabs. The lesions in the brain stem were confined to the nuclei associated with the trigeminal nerve tract. The results indicate that the virus produced both lesions in the respiratory mucosa and central nervous system, and suggest that the virus might have reached the brain stem along the trigeminal nerve tract as the predominant route.