Abstract
Intranasal inoculation with 15-100 cells of the proliferative form of toxoplasma (Tp) caused no clinical infection in piglets about two months old. In inoculated piglets, no rise in dye-test titer was observed. No positive T.S.C. skin test was given by any one of them. Infection occurred when more than 1, 000 cells of Tp had been inoculated. These results seemed to indicate that the intranasal route was useful for infection.
After intraperitoneal inoculation with 200 to 2, 000 cells of Tp, a rise in dye-test titer was observed and a positive T.S.C. skin test was revealed, although no inoculated piglets showed any clinical signs. It was considered that these piglets were suffering from the subclinical infection. Those piglets which had been given more than 20, 000 cells of Tp were infected successfully with clinical symptoms, giving positive dye tests and T. S.C. skin tests.
In swine artificially infected, leukocytes increased in number, neutrophils increased in percentage with shift to the left of nuclei, and decreased in number but no change was seen in the number of reticulocytes. These hematological findings were considered to have a very important significance for the differential diagnosis between hog cholera and acute toxoplasmosis of swine.
