MALIGNANT CATARRHAL FEVER IN FARMED RUSA DEER (CERVUS TIMORENSIS): 2. Animal Transmission and Virological Studies

SUMMARY A disease with clinical signs and histological lesions similar to malignant catarrhal fever in cattle was transmitted from Rusa deer (Cervus timorensis) to rabbits. This was accomplished on 3 separate occasions, and the disease was serially passaged in rabbits up to 11 times. The clinical signs in affected rabbits were pyrexia, depression, anorexia, mucopurulent conjuctivitis, nasal discharge and diarrhoea. These signs were seen in 27 of 38 inoculated rabbits with the mean incubation period being 12 days (range 8 to 20 days). Histologically, affected rabbits exhibited mononuclear perivascular cuffing and vasculitis in the brain, heart, liver and kidney. Lymph nodes and spleen showed destruction and loss of mature lymphocytes and lymphoid follicles and an increased number of large lymphoblastoid cells. These clinical signs and lesions were not detected in control rabbits. The disease was not transmitted to cattle, sheep, guinea pigs or mice, nor was an agent isolated in cattle, deer or rabbit tissue cultures, or in chicken embryos.