Kathleen and Sparky,
 
>Sparky, 5 yr old ferret with fluid build up in abdomen and enlarged heart.
>Vet said its not congestive heart failure.  He is on lassix (.15cc BID) and
>cedoxin (.2cc once a day)
 
This is a little confusing to me.  A ferret with fluid build-up in abdomen
and an enlarged heart usually has one of two diseases: Congestive Heart
Failure or Heartworm Disease (if you are in a heartworm endemic area).
Congestive Heart Failure is a progressive disease which is usually
controlable for a period of time with lasix (a diuretic--pulls extra fluid
out of lungs and abdomen. dosage is 1/2 to 1 mg/#/day.I don't know what
concentration your lasix is so its hard to know if he is on the correct
dosage.) and Digoxin (I assume this is what you meant rather then cedoxin
---again without the concentration I don't know that the dossage is correct)
Lasix will make him drink and urinate more, and if used in too high dossage
or in a dehydrated ferret it can be hard on the kidneys.  Digoxin can be
very toxic if the dossage is too high (the theraputic and toxic dosages are
close together).  A blood digoxin level is not usually practical because we
do not have a normal range established for the ferret and blood is usually
drawn under anesthesia which is stressful to a ferret with heart failure
(without anesthesia it is even more stressful to a ferret with heart
failure).  Signs of toxicity from digoxin include lethargy, vomiting, poor
appetite, diarrhea.
 
It sounds like your ferret has congestive heart failure----remember this can
be managed for a while but will progressively get worse.  The fluid in the
abdomen usually continues to to get worse and your vet may have to
periodically draw some fulid off the abdomen to keep him comfortable.
 
Heartworm disease is diagnose by a blood test called an occult heartworm
test.
 
Good Luck
 
Dr Weiss
301-299-4142
[Posted in FML issue 1322]