Malignant catarrhal fever III. Experimental infection of sheep, domestic rabbits and laboratory animals with malignant catarrhal fever virus.

Five of 19 sheep became infected when inoculated with a virulent strain of malignant catarrhal fever virus isolated in Kenya One of the infected animals was killed in extremis; its blood and lymph node suspension reproduced the classical disease in three steers. Calves exposed to these sheep did not become infected during 89 days of close contact. The Kenya strain of malignant catarrhal fever virus infected rabbits, guinea pigs and hamsters, producing occular and nasal discharges, paralysis and death. The virus recovered from these animals in cell cultures produced disease in rabbits and steers. Neutralizing antibodies were found in the rabbit sera. Infant mice, chicken and duck embryos were refractory to infection with malignant catarrhal fever virus.