Abstract
The visceral organs, lymph nodes, brain, eye and striated musculature from 12 swine suspected of the latent infection depending upon gross lesions of the lymph nodes and liver, and from 45 apparently healthy animals having no gross lesions were examined for presence of toxoplasmas by microscopic observation on smear preparations of the organs as well as mouse inoculation test. Among those with gross lesions, 7 animals showed positive results by both the microscopic observation and the isolation, and the remaining 5 animals were proved to be infected by either the isolation (3 animals) or the microscopic observation (2 animals). In the cases having no gross lesions, 5 animals were found to be infected by the isolation of the organisms. In the swine with gross lesions, the organisms distributed widely in the organs examined, except for the gastro-intestinal tract. In the swine having no gross lesions, the striated musculature, brain, lung, stomach, large intestine and eye were found to be favorite sites of localization of the parasites. Of 51 strains from the swine having no gross lesions, 37 were shown to be capable of killing mice, while 77 of 94 strains from the animals with gross lesions were of low virulence for mice.
