Shouldnt have done any damage then. Have you taken the carbon out now? You probably have, but just checking.
Could just be the angle, but the swelling looks to me to be going down a bit, the white powder could be a reaction to the meds or could be the infection spreading, its hard to tell. If hes still active and feeding, its a good sign though.
He really needs issolating and using antibiotics.
As i doubt that anti internal bacteria med by interpet is up to the job.