ABSTRACT
Cysticercus fasciolaris, the larval form of Taenia taeniaformis is commonly encountered in rodents most often in mice and rats through contaminated feed and bedding materials. The infection is asymptomatic and is considered harmless, but its presence in the laboratory mice/rats could lead to misinterpretation of results for biological experiments. The course of infection and pathogenesis of induced C. fasciolaris was studied in Swiss albino mice. The number of established cysts were not significantly different during the course of infection. The mean diameter of the cysts and the metacestode were significantly different during the course of infection reaching a maximum size of 8.1 +/- 2.2 mm and 80.4 +/- 20.2 mm, respectively on 45 DPI. Histopathologically, on 15 DPI, the duodenum of the affected mice revealed cross sections of early larval stage of C. fasciolaris. On 30 and 45 DPI, the liver showed tract of migration of C. fasciolaris larvae with a thick zone of inflammatory reaction and encapsulation against mature larvae in liver. The routine spontaneous Cystucercus infection is clinically asymptomatic in these animals and is considered harmless. The present experimental infection also followed the same course resulting only in asymptomatic colonisation of the parasites.