The following results were obtained in the present study concerning the effectiveness of thiabendazole upon the larvae of the migrating stages. In the early observation group: The average number of larvae of the group treated with single dose and the group treated with three doses were reduced in proportion of 52.2%, 58.5 % respectively compared with control group. In the late observation group: The reduction rate in the group treated with singel dose and group treated with three doses were 59.3 % and 63.2 % respectively compared with control group. The reduction rates of larvae from liver and lungs in the early drug administration group were 72.9 % and 59.7 % respectively, and 14.9 % and 54.8 % in the delayed drug administration group. In the group of drug given before and after infection, the number of recovered larvae were reduced 42.2 % and 31.1 % respectively compared with the control group. The peak number in organs was delayed 1 to 2 days in the treated group than that of control group. The survival period of the infected mouse was prolonged by the drug administration. The pathological changes were reduced by the administration of the drug. Through above results, it was concluded that thiabendazole reduced the number of migrating larvae and delayed the normal migration of the larvae in tissues and reduced the pathological changes in the tissues.
