In this study, three different doses of LCM (0.12, 0.5, and 1.60 mg in 0.18 mL) were applied under the embryonic disks of specific pathogen-free Leghorn chicken embryos after a 30-h incubation. Incubation was continued for 80 h, at which time all embryos were evaluated macroscopically and microscopically. There was growth retardation in all of the LCM-treated groups. Major malformations increased in a dose-dependent manner and were mostly observed in the supratherapeutic group. Based on our data, LCM may cause growth retardation or major congenital malformations. Nevertheless, more extensive investigations of its reliability are needed.