To Marshall:
If your vet did not carefully check the entire length of the intestine,
something may have been missed.  The symptoms you describe sound suspicious
for a blockage.
 
IS IT A BLOCKAGE....symptoms to look for:
  1. "The ferret was fine yesterday; today it is lethargic and will not
     eat or drink".
  2. Has not pooped for several hours, no poop in cage if cleaned
     recently.
  3. May see very small amount of black, runny stool.
  4. Eyes sunken and looking as if in pain. Eyes look sunken due to pain
     and/or dehydration.  Ferret reluctant to move around.
WHAT TO DO......
If you suspect a blockage and cannot get to a vet (or vet is clueless),
give by feeding syringe or eyedropper 12cc warm water with 2" hairball
remedy mixed in.  Give same amount every hour for 4 hours.  If the ferret
is dehydrated (kills more ferrets than the actual blockage does), this will
help.  If the ferret is alert and gum color is pink and if vet help is
unavailable, I try this for a maximum of 10 hours before resorting to
surgery.  Keep in mind that xrays and barium series often show nothing and
the time it takes to do a lot of testing may cost the ferret its life if it
is pale and unresponsive.  While I have "cleared" 3 cases with
water/hairball remedy in ferrets brought to shelter in distress (1 cherry
pit, 1 meal of Blue Ice cooler substance, 1 huge hairball, 1 condom--fatal),
we had to give up on the latest one and do surgery: a pistachio nut.
 
To Ulrike:
Consider Ferret Bloat Syndrome as a possiblity.  Treatment is antiacid and
antibiotics.  If this is the case, it is a bacterial infection and may
respond to antibiotics.  Would try this before resorting to draining off
the abdomen, but this is also an option to relieve the distress if it is
fluid-caused.
 
Ferret Rescue of the Western States
[Posted in FML issue 2341]