To find vets go to
http://www.ferretcongress.org
and scroll down the crit refs to the links for vet listings.
 
Hind end weakness is a general and non-diagnostic symptom in a ferret
unless it happens in some unusual way.
 
The single most common cause by a wide margin of inability to urinate
in a neutered male ferret is prostate enlargement secondary to adrenal
neoplasia.  Look up the words Propecia or Proscar with the from line
from AFERRETVET in
http://fhl.sonic-weasel.org
 
Bladder stones can also happen but far less commonly.  Again, check in
that resource.  Don't select a "from" from that search, just look under
stones and under uroliths.
 
Yes, there can be problems with the spinal cord which can affect
urination and defecation, but those are quite rare in most.  Yes
bladder infections can happen, but those often trace back to adrenal
neoplasia, too.
 
If you can think of it and it is ferret health related it's most likely
in those Archives...
 
Pretty much everything else plus a large number of health things are in
the FML Archives whose addy is in the header of every day's FML.
 
How old is this ferret ?  (Actually an important question)  What tests
have been done?  What results?  What symptoms?
 
Please, don't judge or weigh people's helping each other.  It is always
good when folks help each other no matter what the question or real need.
Sometimes people don't have the background to answer a certain question,
or missed it due to other responsibilities in life, or the info given
wasn't enough to give insight, or whatever else went wrong.  I realize
it was just stress talking in that line on your post, but now you should
have somewhere to begin searching for what you need.
[Posted in FML issue 4600]