We are minded to tell them.
They're away for a while - back next weekend. Cat hasn't been seen and food not been touched for a few days. DH been up there to feed let it in/out at least twice a day, religiously.
There's not much they can do but it might be chipped or it might have returned to previous address - if we had more info we could check this.
Fairly new neighbours so we don't know then very well hence indecision. They have no children so might be child subsitute - ie a real big deal.
At the moment we are coming down on 'tell them'...but over to cat lovers of mn...