Immunization of neonatal lambs against the larvae of Taenia hydatigena, using viable eggs followed by chemotherapy

The subcutaneous injection of viable eggs of Taenia hydatigena into neonatal lambs induced 100% protection against the development of viable T. hydatigena larvae from an oral challenge. However, contrary to some published results, no protection was induced against a simultaneous infection with eggs of T. ovis and Echinococcus granulosus.The short-acting partial resistance to oral infection with T. hydatigena eggs, transferred from infected ewes to their lambs, was not enhanced by hyperimmunization of the ewe. In the lamb, this resistance did not interfere with the development of subcutaneously injected T. hydatigena eggs into immature larvae, or with the consequent induction of resistance to an oral challenge with T. hydatigena eggs. The immunizing lesion regressed rapidly after treatment of lambs with Mebendazole, and after 6 months the lesions were negligible in both treated and untreated lambs.