I have not dealt with this in ferrets, but have dealt with it in cats and
dogs.
 
My little dog Sweetcakes had a heart murmur from birth.  She lived to be
almost 20, and only had to take meds the last 3-4 years of her life for her
heart.  Also our poodle RJ had congestive heart failure but with meds, lived
5 years after diagnoses.
 
My ex kept our cat that also has a heart murmur.  He is still going strong
thanks again to meds.
 
All of these animals got three basic meds, in differing dosages.  Lasix, a
diurectic, Theodur, which relieves congestion in the lungs (I take it for
asthma), and a newer heart med, Enacard.  The first two are traditional
standbys, the last a very remarkable drug that really improves quality of
life.
 
You didn't say how bad the murmur was nor how old the ferret is.  Sweetcakes
had a murmur her entire life.  Murmurs are graded on a scale of either 1-5
or 1-6, I can't remember right now.  1 is the least, higher is worse.
Sweetcakes had a grade 5 for several years before her passing.  When the
murmur is bad enough, I can hear it too.  It sounds mushy and wooshy.  Very
technical terms I know.  When they are mild, they are hard for a layman to
hear.  Also be sure your vet uses a smaller stethsescope (?) when listening
to ferrets.
 
When the heart troubles get bad, you get a lot of coughing (from fluid build
up around the heart and lungs) and you will eventually get kidney problems.
The kidneys are affected due to their enormous requirements for blood.  When
the heart weakens, it pumps less efficiently, thus reducing the flow to the
kidneys (and other parts of the body).  So one side effect is diminished
kidney function, but even this can last awhile without greatly affecting the
animal's quality of life.
 
A sign of poor kidney function is large output of urine.  The kidneys no
longer process the urine correctly, not concentrating it, so you get large
amounts of fluid with hardly any color to it.  It looks like water.
 
It is sometimes hard to balance the need to get rid of fluid retention and
electrolytes and dehyrdation.  But this usually only becomes a problem in
the last stages.
 
My animals have all done fine with meds for several years.  They do slow
down, and tire easier than when younger.  But they are normally not in pain
and enjoy things quite well.  RJ would still chase a tennis ball as hard as
he could, just not as many times as when he was young.
 
I would think that all of this would apply to ferrets, especially since it
does apply to cats.  It can be managed with several drugs and does not
necessarily mean an immediate, horrible problem.  One thing you will notice
is a broadening of the ribs, due to the enlargement of the heart.
 
Good luck with your fuzzy.
 
Maggie Mae
 
what i wouldn't give to find a soulmate
someone else to catch this drift
and what i wouldn't give to meet a kindred.......a. morissette
[Posted in FML issue 2155]