Toxocariasis is a disease of unspecific clinical manifestations in human beings and some animals forming a condition known as visceral larva migerans. Effective Toxocara canis (T. canis) control should destroy the dormant hypobiotic larvae in the tissues of the reservoir hosts. Embyonated egg antigen is intended to be evaluated in rabbits where15 New Zealand rabbits were divided into 3 groups; immunized group that injected with three doses of T. canis egg antigen (First dose with complete Freund's and two successive doses with incomplete Freund’s adjuvant); control infected group and adjuvant control group. At 30th day from the beginning of the experiment, all groups were infected with 10,000 T. canis embryonated egg. Blood samples were collected periodically for measuring antibodies titer by ELISA. Postmortem and histopathological investigations were done. The efficacy of egg antigen protective immunity was evaluated by; the positive antibody titer, retention of larvae in the liver, hepatic eosinophilic granuloma formation, number of the milky spots on the liver surface and lung resistance to the infection. These parameters were detected obviously in the immunized group than the non immunized ones. Consequently, production of this product is recommended where its preparation is simple, easy, fast and economic and may be used as role of vaccine program against the parasite infection in thesusceptible hosts.

In this study, a combined Trivalent vaccine against ND, IB and M. gallisepticum was locally prepared and evaluated in comparison with other locally prepared Bivalent ND and IB and monovalent M. gallisepticum vaccines. The obtained results were promising for this locally prepared Trivalent vaccine and the immune response was outstanding starting at the 2nd week post vaccination and showed extended raising allover the experiment period. The immune response of chickens vaccinated with the Trivalent was shoot up post boostering at the 8th week post 1st vaccination. These results were confirmed and supported by the challenge tests using the virulent strains of the three pathogens. So it could be recommend that the production of this Trivalent ND, IB and M. gallisepticum will help in the control of the three diseases and their complications.