Thanks for the replies.
The wound is a deep one, and it looks like someone may have tried to dig the chip out with a knife. A horrible thing to do but it's not the first time I've heard of it. The person I got it from said it was in a fight with another dog, but it certainly doesn't look that way.

I thought I would post around about it, in case the chip was removed and nothing shows up when we take it to the vet.