I think that it is important here to remember that dilated hearts are
from cardiomyopathy that has been present enough to cause that muscular
effect over time, and that the symptoms at death are consistent with a
cardiovascular cause, and also that right now the cause is not firmly
established so it is way too early to draw conclusions based on temporal
factors.
 
Plus, in the same time frame you lost one from rampant pneumonia, and
that while rampant pneumonia would show up in a plain old necropsy, a
lesser infection that could be too much combined with heart disease would
not.  Remember that the word on necropsies is that the vast majority of
the causes of death in mammals that are not obvious with a necropsy need
timely pathology done to find out what actually truly occurred.  There
is a figure -- I think in the Ferret Mailing List Archives
<http://listserv.cuny.edu/archives/ferret-search.html>
but perhaps in the Ferret Health List Archives -- on that.  There are a
huge number of things that just can not be told without pathology done.
Without pathology all that exists is a monetary settlement unless there
are other such cases in which the pathology has been done (I have not
heard of any) and monetary settlements can happen for a range of reasons.
 
There IS a known case of a very small sized female who appeared to
possibly have trouble with the melatonin implant dose, but that is not
firmly known as the cause, especially since larger doses per weight had
been seen in other ferrets.  She was part of a study and she became very
(very) lethargic for an extended period, then rebounded.  The cause
remains unknown, but it is possible that she was particularly sensitive
to the tiring effects of melatonin due to some individual factor, or
her size, or both.
 
What has happened on the pathology front?  Did the preps to get that done
happen rapidly enough?  The window is a short one.  Remember that if the
tissue isn't in formalin within 48 hours then nothing at all can be
learned from it, and with some aspects of the digestive system like the
gall bladder and intestine that needs to be done by the vet within hours
of death.  See:
http://ferrethealth.org/archive/browse.php?msg=YG10682
http://ferrethealth.org/archive/browse.php?msg=YG647
etc.
 
How large was this ferret?
 
It is possible that the stress of the large bore may have been factor
given the signs of preexisting heart disease discussed on the FHL,
especially is combined with the limitations of a lung infection that
simply wasn't overt enough to be spotted on a simple necropsy, though
the latter two together could have been enough, or *maybe* a ferret who
is already dealing with either or both of those problems is not a good
candidate for something that can further deepen sleep.  (Note that is a
*maybe*.)
 
Remember that she had already been on oral melatonin, and that the body
itself produces melatonin in response to darkness.
 
(Melatonin serves MANY functions in the body.)
 
The only way to KNOW what happened here would be through timely pathology
before tissue degradation.  The enlarged heart alone says that this was
already a compromised ferret with cardiomyopathy.
 
-- Sukie (not a vet)
Ferret Health List co-moderator
http://www.smartgroups.com/groups/ferrethealth
FHL Archives fan
http://ferrethealth.org/archive/
replacing
http://fhl.sonic-weasel.org
International Ferret Congress advisor
http://www.ferretcongress.org
[Posted in FML issue 5033]