More often than not the only way to find out what is happening with
mysterious ailments is to have a necropsy with pathology done, and
sometimes also tests to check for some sort of accidental poisoning (which
certainly has happened at times in the past) -- not just a look-see but
checking by those specialists, too.  One thing which is often repeated here
is that necropsies save lives; sounds strange until a person considers it.
 
It's always a sad situation when a person has to mention this.  Can't
recall one time that I've had to say this without feeling like crying.
Am very sorry that you are going through this.
 
These sorts of situations get reported here maybe once to three times a
year, except when there is something causing a new epizooic and a lot
appear, and then those areas have to shut their gates and contain it till
it is figured out and handled appropriately.  Fortunately, there have
been some times when the pieces came together, the isolations and testing
happened, and the illness was controlled till it disappeared.
 
If this is continuing you will not want to add any ferrets till you have
a diagnosis and a solution in terms of what to do to be safest for the
ferrets.
[Posted in FML issue 3127]