Have You Ever Lost A Pet?

I have never lost a pet, and it's a big fear for me. I have two cats that have lived indoors their whole lives. If they somehow got outside, it would probably be very scary for them. They never learned how to deal with traffic, and the only people they ever met were friendly to them, so they would probably be too trusting. They both have microchips, but no ID collars, since they really hate collars and I'm afraid they might hurt themselves. But even if I did, I doubt that anyone would check for their owners or if they have chips. Where I live, common mentality is that it's normal for cats to live outside, so I would probably never see them again... I really hope I'll never have to go through this.