I just went with my friend to a ferret expert vet in roanoke Virginia and
her ferret was diagnosed with cardiomyopathy.  The vet didn't say anything
one way or the other about feeding.  He did put the ferret on endocal to
lower his blood pressure and taurine.  He also recommended a diuretic
(lasex, I believe) for the fluid build up.  My spellings on the medications
may be wrong.
 
We caught the cardiomyopathy early, and therefore, the vet gave him
anywhere from 6 months to two years (the upper end only because no
irregular heartbeat or murmur was heard).
 
You may want to discuss these options with your vet.  I have never heard of
paralysis being associated with this condition, but a diuretic may help his
circulation adn improve his condition.
 
good Luck!
Paige
[Posted in FML issue 2682]