There is a gene in ferrets that is believed to be associated with
deafness.  It is the same gene that is associated with the Panda and
Blaze patterns.  These also usually have white feet (Fara Shimbo calls
these socks as opposed to the white feet associated with mitts).
 
Some ways to tell if your friend Mojo has this gene are to look for white
'kneecaps' on the hind legs, a white 'stripe' down the top of the head -
it could be just a spot or two instead of a nice stripe, a slolid white
head - that is a REALLY wide stripe in effect.  These ferrets also have
tendacnies toward slightly wider heads with smaller eyes further appart
but that is often really hard to see.
 
There are other reasons a ferret could be deaf but this is unfortunately
the most common.  Through questionable breeding practices this flaw of
deafness has been promoted through the desirability of the 'neat' patterns
that are associated.  We have this gene in a large number of our ferrets
but we don't go to a great deal of trouble to promote it (but we haven't
tried real hard to eradicate it either since so many people want these
patterns - tough call to make unfortunately)
 
Oh by the way folks, I early made some comments about what is a 'sable
mitt' (months ago).  What the local breeders refer to as a Sable Mitt is
a ferret of sable color that has this gene causing the white feet but not
the pronounced stripe.  I'm not comfortable calling the two different
kinds of white feet mits but the common convention is to do so.  We got
two of these 'Sable mitts' out of our breeding program this year - I
called them 'Sable Blaze Wanna-bes' but thats just me.
 
bill and diane killian
zen and the art of ferrets
[Posted in FML issue 1247]