Cathy and Reba,
Many times when a ferret is ill they become weak in the hind legs.  I
can think of a couple of possibilities from the history and results you
mentioned.
 
1)Heart Failure---I have seen cases where the only symptom initially is weak
back legs.  The bloodwork is usually normal.  This is diagnosed with X-rays.
The heart is larger then normal and appears round (rather then elliptical).
Also the lungs start to fill up with fluid.  From what you described on the
X-rays it sound like this is a good possibility.  This is treated with lasix
(to help remove the fluid build up in the lungs) and digoxin (strengthens
the contraction of the heart).  If this is the cause she should be up and
walking with 2-5 days of treatment.  The goal of treatment is to alleviate
the symptoms and make the patient as comfortable for as long as possible.
 
2)Aleutian Disease---This is a disease caused by a chronic viral infection.
This infection causes the ferrets protein level to increase (in the blood we
measure 2 types of proteins--albumin and globulin----this causes an
increased globulin level) Over time the ferret has such a stimulated immune
system which leads to more serious problems with the kidneys and other
organs.  This is contagious to other ferrets.  There is a blood test to
diagnose this disease which is run by United Vaccine company.
 
There are many other conditions that can cause weakness in the rear legs
such as: GI obstruction (can see diarrhea,vomiting,weight loss),
Lymphosarcoma (can see enlarged lymph nodes,elevated lymphocyte count), Disc
injury (back pain).  Feel free to contact me for more info.
 
Good Luck,
Dr Weiss
301-299-4142
[Posted in FML issue 1412]