We have a white ferret/ yellow.  Don't know why but he is.  Maybe diet?
We used a Ferrret whiting shampoo, Shepard and Green.  Made our boys hair
on his tail fall out and turn brown first.  So be carefull what you use.
I just deal with the yellow Ferret, than to take a chance and harm him
again.  I use Tomlyn Ferret shampoo or baby shampoo when needed.  Wet rag
helps between washings.
 
Carol
[Posted in FML issue 4632]