Eu acho que é o conto clássico de Isaac Asimov, "Green Patches" , encontrado em "Nightfall and Other Stories ".
“That is correct. Saybrook said so and we corroborate him. After the rats, the pet cat of one of the children was obviously affected. When it finally kittened, the kittens were not born with closed eyes but with little patches of green fur. There was no tomcat aboard.
“Eventually Saybrook had the women tested. He didn’t tell them what for. He didn’t want to frighten them. Every single one of them was in the early stages of pregnancy, leaving out of consideration those few who had been pregnant at the time of embarkation. Saybrook never waited for any child to be born, of course. He knew they would have no eyes, only shining patches of green fur.