An unusual migration of Taenia hydatigena larvae in a lamb.

The liver and lungs of an four month old, female dead lamb was referred to Veterinary clinic of Shahrekord, Iran by a sheepherder due to outbreak of an unknown disease that caused four deaths in the livestock over a period of one week. Post-mortem examination of the liver showed a massive infection of Taenia hydatigena larvae. Diffuse, spiral and haemorrhagic tracts made by migrating larvae were seen throughout the liver. Large brown to red areas of haemorrhages also appeared on the liver cut surfaces. All the recovered T. hydatigena larvae from migratory canals and hepatic surfaces were all immatures. There was no mature cyst formation. No evidence of pulmonary involvement was found. Histopathological examinations of the liver revealed numerous sections of migratory tracts filled with red blood cells, fibrin and tissue debris. Sections of T. hydatigena larvae were observed at the ends of migratory canals. Hepatocellular degeneration, necrosis, fatty change and infiltration of mixed inflammatory cells, including lymphocytes, plasma cells and macrophages were associated with these tracts. This article reports outbreak of an unusual and severe hepatitis cysticercosa with striking hepatic lesions that caused mortality in a livestock.