Gregory's Server@kudra Devils advocate mode engaged...
They might have been in hospital or something? People can get busy enough to not reply to every message they receive... I know, I've been there, it sucks, you feel guilty about it too, then that guilt turns into anxiety when people push you for a response..
I'm certainly guilty of missing messages for days and not replying for weeks...
Following up was the right thing to do none the less..
@johnmclear sure, loads of things could have happened, but I've not had it happen before when someone doesn't have the courtesy to confirm the animal/s are well and usually some kind of thanks, especially if they hope you might sit for them again in future. They did follow up saying they got home very late, but there's been almost 3 full days since then.