From:
Dr. Bruce Williams
Date: 2001-03-03 10:32:00 UTC
Subject: Re: enlarged spleen
Alicia is very correct on this one. Let me add a little more
detail. Splenomegaly is a sterotypical response to chronic
smouldering inflammation in ferrets. While it is most often seen in
response to chronic inflammation in the GI tract due to Helicobacter
or prior ECE, actually any chronic inflammatory condition can cause
it. Chronic inflammation is a site of liberation for many chemicals
(called cytokines) which serve to attract other inflammatory cells,
modeulate the inflammatory response,etc. While most stay locally, a
small amount gets into the bloodstream and travels around.
These compounds have the ability to turn on the maturation of white
and red blood cells in the spleen. this is not particularly unique
to ferets, but we see it in other species as well. The best proof of
this phenomenon was a study done about 15 years ago in rats. A group
of rats was injected with sterile turpentine in the hindleg, which
set up a chornic inflammatory lesion (with no infectious component.)
Lo and behold, five days later, they all had enlarged spleens which
were packed with immature white blood cells - necessary for fighting
this infection. Red blood cells are generally also produced in the
spleen in inflammatory lesions, because another side effect of
chronic inflammation is a mild anemia in many cases.
95+% of enlarged spleens, when biopsy or aspirated, come back with a
diagnosis of "extramedullary hematopoesis" (the doctor name for a
bunch of immature red and white blood cells.) Less than 5% are due
to neoplasia of the spleen (usually lymphoma, but occasionally you
see vascular neoplasms.)
What do we do with enlarged spleens? Well, if they get really big,
they can rupture. Large spleens also can displace other organs and
cause ferets to become lethargic and inappetent. (Imagine if you had
a 40 lb. spleen inside you - you wouldn't feel tip top either!)
If there is no easily addressed site of inflammation, and the spleen
is large enough for the animal to be symptomatic, we pretty much just
remove it. I have never seen splenectomized animals develop systemic
infectious disease, which is a concern in dogs. Also, I have not
really seen significnat benefits in ferrets due to the presence of
maturing blood elements in the spleen. They never seem to get
released into the peripheral circulation - the spleen just gets
bigger and bigger. I've seen critically anemic animals die with
loads and loads of immature red blood cells in the spleen. So, to
minimize the risk of rupture and make the animal feel better,
splenectomy is often performed, and is usually successful.
With kindest regards,
With kindest regards,
Bruce H. Williams, DVM
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Health-list
> I am sure you will get plenty of responses on this topic we have
seen it
> quite a bit in the shelter. An enlarged spleen can be an indicator
of a
> chronic ( long term) infection. This can be something as simple as
an
> undetected ulcer or helicobacter from stress or as complicated as a
> gingivitis, prolonged ear mite infestation, bladder condition,
etc. Many
> times the animals show no signs of discomfort and the infections
run there
> course. The modest approach would be for you vet to run an
antibiotic
> regiment and see if the problem resolves itself. Many times it
does. If
> not then there is the possibility a stronger antibiotic is
required or if
> any nodes are enlarged a check to make sure there is no lymphoma
present.
>
> I send good healing thoughts your way for Sundance and hope a
speedy
> diagnosis is rendered.
>
> Alicia, shelter Mom
> Ferret Wise
> www.ferretwise.org
>
> DISCLAIMER:
> This e-mail is provided for general informational purposes only. It
is
> in no way intended as a replacement for a consultation with a
qualified
> licensed veterinarian. If you are concerned about your pet's
health, you
> should seek the advice of your regular veterinarian as soon as
possible.