Several of my ferrets get very thin tail hair by the end of the summer,
sometimes accompanied by that rusty crust, sometimes not (no crust this
year, but still thin tail hair).  None of them have great looking tails by
late summer.  Every fall, after they shed and look really ratty for a few
weeks, they grow nice thick tail hair that lasts at least through the
spring.  This is not related to adrenal disease, which two of my ferrets
also have.
 
Blessings
Judith
 
P.S.  Still hoping to hear about flax seed oil dosage for the two adrenals.
[Posted in FML issue 3201]