Nancy-
 
I had a similar problem with Elliott about 6 months after I got him - he
was about a year then, a rescue, and was eating ferret chow - I switched
him over to my blend at the time which were all, good quality kitten/cat
foods - chicken based.
 
He had teeny tiny little 'spots' on his skin, he was scratching all the
time, his fur got rough and started thinning out.  First we did a skin
scrape to look for bugs, but it was negative.  We tried steroids but that
didn't help at all.  We tried antibiotics but that didn't help.  I switched
from Tide to Ivory and used perfure-free, dye-free fabric softeners (which I
still use today), but that didn't help.
 
Then my vet thought it might be a chicken allergy, so I switched him to
Proplan Turkey and Barley cat food.  He said it would take about 3 weeks
before I would see any difference.
 
Well, Elliott was a different ferret after the food switch!  He gained
weight, his fur grew back in, it got soft and shiny again, the spots
disappeared, and he stopped scratching!
 
So now he eats Proplan Turkey/Barley and Iams Lamb and Rice - both high
protein, high fat cat foods - naturally preserved - and is doing great.
 
I have another ferret who recently developed similar symptoms, and I'm
trying this first.  I moved him in with Elliott so they're eating the
same food now, and hopefully it will something simple like a food allergy.
 
It's worth a try if nothing else has worked so far and your vet is stumped.
 
(BTW, has your vet done a skin scrape to look for litle bugs?)
 
Debbie Riccio
WNYFLFA
Western New York and Finger Lakes
   Ferret Association
Rochester, NY
[Posted in FML issue 1457]