I have been checking your message to see if there is any responses. I have a cwd and i noticed last week that his front left paw has the same think, although, not as big. I took him to our vet and the vet side more than likely it is a fracture and would be too hard to splint and should heal on its own with time. I am feeling very uneasy with this diagnosis and the swelling has seemed to go up his leg "ankle?" area a bit. I would be really interested what your vet says is the problem and what the treatment would be. Looking forward to hearing any posts or the diagnosis from your vet. Thanks Billie