Late effects of embryonic allylestrenol treatment in chicken.

Allylestrenol when applied to chick embryos on the 9th day of incubation or on the 9th day of incubation and at hatching brought about a severe purulent inflammation of the oviduct at 6 weeks of age in 50% of the animals. Treatment at hatching only had no effect whatsoever. The findings suggest that allylestrenol must be applied with caution during pregnancy.