Margaret Zick asked about the potential for mad cow disease to spread to
other critters, like ferrets.  I have been following the scientific debates
on another listserv devoted to emerging infectious disease.  BSE (bovine
spongiform encephalopathy; aka, mad cow disease) probably poses no threat to
ferrets.  It's still HIGHLY debatable whether the 10 early-onset cases of
Creutzfeld-Jacob disease in Britain are associated with the bovine version
of the same disease.
 
However, there *is* a similar disease in minks known as transmissible mink
encephalopathy (TME).  (Sorry for all the multi-syllable words.  It's hard
to keep track of the abbreviations sometimes, too.)
 
TME is also very unlikely to get passed onto ferrets because the
transmitting agent, called a prion, is contained in the brain and spinal
tissues, and at least in cattle, in the retina, as well.  For ferrets to get
TME, they would need to be fed food made from infected mink neural tissue.
(I know--yuk!) So, even if the TME prion were biologically capable of
causing disease in ferrets, it's almost impossible that domestic ferrets
would EVER be exposed.  This is not to say, however, that if North America
ever experiences a major outbreak of TME in minks that
state/provincial/county officials won't go off the deep end and start
outlawing ferrets or other mustelids out of fear or stupidity.  In North
Carolina, county officials act as if ferrets are rabies magnets and assume
that any stray ferret is rabid.  I would wager that they would handle a
prion-based disease with even less common sense.
 
--Jeff Johnston
[Posted in FML issue 1529]