Thanks for the comments guys, just a quick update. The swelling on his neck has gone almost completely, however his mouth area is still swollen on both sides.
I have just got back from the vets, he said he was unsure what the problem was but he wants me to take him back on Monday so he can be put under anaesthetic, and explored more. The vet also advised that if there is fluid inside the swelling, he will send a sample away for testing which would hopefully get back for Friday.
Wish us luck guys!
Also if anyone else has had experience with anything similar i would be keen to know.
Thanks