I have two ferrets, one with soft fur, the other with a rougher coat.
Here is a brief description of each:
Chloe: age: 1 yr, 8mos.  Chloe was neutered and descented at 8 weeks (?) of
       age.  I got HIM from a pet store
Sabrina:  age: 1 yr, 9 mos.  Sabrina was spayed but not descented at 6
months of age.
 
They are both fed Iams Eukanba chicken and rice mixed 3:1 with Totally
Ferret.  I have been given many theories as to the difference in coats
including gender, age at neutering/spaying and descented or not.  I have
noticed that Chloe's coat improved this winter after I switched to Iams
Eukanuba (from Iams kitten).  (I must have the only ferrets on the planet
that don't like ferret-only foods.) But, I do not have the definitive answer
as yet.  Thus far, the only correlation I can find with age at neuter is
that Chloe, as a male, only weighs 2 lbs.  From what I have seen this is a
little on the light side for male ferrets (Sabrina weighs 1.5 or so).  But,
I am sure many others out there don't have this experience with their pet
store ferrets so who knows.
 
-Courtney
[Posted in FML issue 1867]