From:
Bruce Williams, DVM
Date: 2001-09-27 07:20:00 UTC
Subject: Re: 3rd degree AV block
--- In Ferret-Health-list@y..., "Shelley Knudsen" <ferrets@t...>
wrote:
> Hello,
>
> I am looking for any information and advice on 3rd degree AV block
in ferrets. >
> When I took him in this morning, we first did an ECG. It revealed
3rd degree AV heart block both times we did an ECG (about 2 hours
apart, the first strip had some problems with lead II). We then did
radiographs (upon the insistence of the radiologists before they
would do an ultrasound). It revealed a rather enlarged heart with a
slight deviation of the trachea. We then went to ultrasound a few
hours later (each time we did something we waited about 1-2 hours in
between to give him time to recover from stress). The ultrasound
revealed very pronounced 3rd degree AV block, the atria were firing
about 4 times for every beat of the ventricles. I don't have the
numbers here in front of me, but basically his heart has compensated
in overall blood flow (normal 42, he was at 40), but there was one
number extremely low (I don't remember what, but I can find out).
>
> My questions are these. What are my options? I'm not sure his
insulinoma can be controlled with just pred, but the surgeons here
will not go to surgery unless we can consistently keep his heart rate
up. He has now been bumped up to 2 mg of pred per day, I don't know
yet how well he will respond to that. What are some drugs that may
have some effect on this that will be okay to use in ferrets, and at
what dose? I know that a pacemaker has been successfully implanted
in a ferret before, but I am pretty sure that it would not be
feasible for me financially (I can't afford the insulinoma surgery,
especially here, but I hate to see him so out of it, so I can find a
way to manage that).
Dear Shelly -
Unforatunately, the treatment of third degree heart block in a ferret
with obvious cardiomyopathy is not something that is routinely
attempted. I am not sure if the drugs that are commonly used in heart
block (atropine, glycopyrrolate, and its derivatives) would be of
much help in total block. (Values for these drugs in ferrets have
been published.) It is likely that there has been a blockage of the
electrical conduction system by the fibrosis which is the hallmark of
CMP, the symptomatology of the AV block will likely be overcome by
signs of cardiomyopathy before too long.
Another very remote possibility, I suppose, would be that the
hypoglycemia is affecting the conducting fibers in the heart, but
that would be a new one on me.
It sounds like heart failure is probably imminent in this little guy,
and treatment of that will become a priority.
With kindest regards,
Bruce Williams, DVM