Ok I'll try and see if the vet near us can at least send a sample to be examined in the mean time I was in pet shop today (I know he knows his stuff) and he said I should try and open his mouth and if it's ulcerated which he thinks looking at the picture that it is.

I was to treat it with iodine, I'm hoping the vet can get something stronger if needed.

Thanks for the advice so far,