Int.J.Vet.Res.(2011), 5,4:212-216 212 Immunization of dog with proteins under 30 kDa molecular weight of hydatid cyst fluid and protoscoleces of Echinococcus granulosus Youssefi, M.R., Hosseini, S.H., Shayan, P., Jalosian,F., Rasaee, M.J. Department of Veterinary Parasitology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Department of Biotechnology, University of Tarbiat Modares, Tehran, Iran.