You're all in for it now.  You stumbled into something that I know just
enough about to be dangerous.
 
Ringworm actually has nothing to do with a worm.  It is a fungal infection.
One of the tell tale signs of the disease is a ring with a flat middle and
raised sides.  Imagine if a worm crawled under your skin and curled himself
into a ring.  That's exactly what it looks like, hence the name ringworm, or
Tinea corporis.  Incidentally, this is the exact same disease as jock itch
or athletes foot, just located in a different area.  The major symptoms are
itching, redness and flaking (or pruritus, erythema and desquamation for all
you science types out there).
 
In animals, the causative organism is Microsporin canis.  It is very easy
to diagnose M. canis in animals.  The fungus will glow under a special
fluorescent lamp, called a Woods Lamp.  You may have noticed your vet
looking at the fungus under one and saying "there are still some active
spores, keep using the medication" (mine did).  I can see no reason why
ferrets would not be able to contract this.
 
M. canis is not the only organism that causes the disease though.  There
are other dermatophyte species that can cause the disease that will not glow
under a woods lamp, however, from my understanding, these are not usually
seen in animals.  There are many over the counter medications that are
indicated for ringworm.  They may or may not work.  This is where I'd like
to tell you exactly what to use, but since I work for the company that makes
the product, it would be too much like advertising (actually exactly like
advertising), so hard as it might be, I'll refrain.  But ask your doctor
what he recommends.
 
Please note that the information supplied in this mail is my own personal
opinion, and does not reflect the opinions of Novartis Pharmaceuticals
Corporation.  Any resemblance to any persons, living or dead, is purely
coincidental.
[Posted in FML issue 2048]