Digoxin is a med to respect.  It has to be used carefully (no overdosing
and keep a chart so you always know what was given when) but it works
wonderfully.  We had one with ventricular bigemini who was expected to
die at any time from her complicated cardiomyopathy and instead once she
had Digoxin she got another year or a year and a half (Can't recall
off-hand which one it was.) of quality life.
 
Here are some places with fine cardiomyopathy info or help to offer,
including on other possible meds:
http://fhl.sonic-weasel.org
http://www.vetsoftware.com/acvc2002-hess2.htm  (a NEW resource)
http://www.miamiferret.org
http://www.heidihoefer.com/pages/ferrets/ferret_heart.htm
http://www./miamiferret.orgfhc
vetheart.com/ (consultants who helped us greatly with Complete A/V
Heart Node Block in a ferret who went on to have about 9 good months
with help)
http://www.smartgroups.com/vault/ferrethealth/cardiomyopathy.txt (but
see the FHL Archives for more recent posts)
and
http://www.smartgroups.com/vault/ferrethealth/ReferenceShelf/
comp_pharm.html (in case you need compounded meds help)
[Posted in FML issue 4589]