Microchips

[Faerie87]

How common is it for a microchip to stop working?

My cat went missing months ago, he is chipped, we think we may have found him however, the cat that has been found has no chip when scanned.

I'm sure it must happen, though I've never heard of it before.
They do commonly move, though. So if a vet/rescue just scans between the shoulder blades it may not pick up a microchip. Is it worth asking if they can scan the whole body?

Best of luck!