Is it possible that this is a mast cell tumor?  When my boys' flair up,
they will often end up as scabs before I find them.  Since they have
now had them flair up on several occasions, I know that the occasional
lethargy I observe is my red flag that a flair up has occurred.  I treat
them with a triple antibiotic cream and they usually go away before
becoming an irritant leading to the scratching, which can reslut in
bleeding and scabbing.
 
New, these may appear as a little blister with increased vascularization
or may feel like a bump under the skin.  They ae hard to see in the fur
with only a visual inspection, but easily noticed if you get your fingers
in your ferret's fur.  Try rubbing against the grain.
 
FWIW, I have had several ferret knowledgable vets advise against removal
on both of my boys with these tumors.  Although opinions are different,
the general consensus is that they do not cause the problems in ferrets
that they can in dogs.
 
Now, that all said, I am NOT a vet.  It is not possible to make a
diagnosis without seeing the vet.  I would suggest you watch carefully
and make an appointment to see the vet the day it flairs up.  That way,
they will be able to observe the sore and let you know.
 
renee :)
[Posted in FML issue 4646]