Hi Marty's Mom,
 
It sounds like Marty might have a chordoma.  This is a type of bone
cancer that ferrets sometimes get.  When it's at the tip of the tail,
it's not likely to metastasize, but it's not comfortable for the ferret,
especially as it continues to grow.  The good news is that removing the
lump and the next few vertabrae down is totally curative, and it's not
a difficult surgery at all.  My ferret Pan had one removed earlier this
year, and now that his fur has grown back you'd never even know that
some of his tail was removed.
 
Here's a website with some more information:
http://www.afip.org/ferrets/chordoma.html
 
and a website with some good before and after pictures:
http://www.ferrets-n-limbo.org/TitusvilleFeaturedFerret.html
 
best wishes,
Regina
 
Regina Harrison  [log in to unmask]
http://users.rcn.com/badriya/
blog: http://badriya-z.blogspot.com/
 
"Is that my business?  Well, what is my business?  Do I know?  Did I ever
know?  Let s not go into that.  You re not human tonight, Marlowe.  Maybe
I never was or ever will be... Maybe we all get like this in the cold
half-lit world where always the wrong thing happens and never the right."
--Raymond Chandler, The Little Sister
[Posted in FML issue 4572]