1) I noticed that a small piece of my fingernail was loose right before getting into my friends car, and then while in the car noticed that the piece was gone,he said that it is possible that pregnant women would ride in the car should I make sure that my friend vacuums his car in fear that a pregnant woman might chas v’Shalom step on that little piece or is moving in a car not considered “walking and stepping on nails”?
2) Does this danger apply to pets nails as well?
The fact that cars moving would be not considered as if the nails were moved, and therefore we still have the fear that a pregnant woman might step on it, therefore vacuuming out the car would be the right choice,
These halachos apply only to Jews and not to gentiles or pets.
Milachim Umonayich- R’ Y. Zilberstein chap. 14 note18