Tetanus is a cut and often highly fatal infectious disease that affects both human and animals; the disease caused by exotoxin which produced by C. tetani. In the current study, we try to get hyperimmune IgY in chicken egg against tetanus toxin and use it as prophylaxis and therapeutic treatment for tetanus. The obtained IgY titer after inoculation of tetanus toxin in chicken eggs was 1320 limit of flocculation (Lf-eq) after 72 hr. IgY in adose of 4500 Lf-eq can be protect donkey after artificial infection by 1 minimum lethal dose (MLD) of C. tetani. While a dose of 30000 Lf-eq IgY intramuscularly two times daily for 2 injections, with 9500 Limit of flocculation Lf-eq IgY intrathecally in subarachnoid space was 100% curative for a donkey which was challenged with 1 MLD of C. tetani. Furthermore, IgY was evaluated experimentally in comparison with IgG in mice. IgY has equally efficacy to IgG in prophylaxis and treatment of tetanus
