If you can, it is good to irrigate out the abscess cavity with a mixture
of 1/2 water and 1/2 peroxide (you can use a syringe or one of those bulb
syringes for babies).  That will clear out the pus and dead tissue.  Be
sure that you or a helper scruffs your ferret while doing this procedure.
 
Once a day is probably enough.  Bacitracin or Neosporin should be fine
with a ferret.
 
Stephen Cox MD (human doctor).
[Posted in FML issue 4675]