Gill, I have no idea Today it seem to be drying out some and you're right he's going bonkers I let him out this afternoon and ran around running into things
That is a nasty looking bite...Our Dog Cookie got a Spider bite about 2 years ago on her left front leg, it was a nasty wound also..The Vet said it was likely a brown recluse Spider that did the damage. Our Dog did not gnaw at her wound but she did lick it often but the Vet never had to put a lampshade on her..Antibiotics cleared our Dog up but it took quite some time for the bite to heal..Cookie still wears a scar from the bite and always will..Good luck with your Dog..