constant tight circles:  See 1

larger circles only when nervous: See 2

1. It was extremely cool to read which portion of the brain would
involved, but it would not be a stroke.

Dr. Bruce Williams has emphasized that it is important with a ferret
who is moving in constant circles that the technical (pathology)
difference between a stroke and a thrombosis be remembered. The reason
I recall that so well is that I think the first time he explained the
difference was in the FML with one of ours (who repeatedly threw clots
due to a complicated form of cardiomyopathy and finally did throw one
to the brain that caused tight circling -- which is upsetting to see --
but also threw a much more serious one to a kidney and would not have
survived the surgery for that when it did not dissolve). That
explanation with both things discussed and the difference between them
might have been before the archives, though. In pathology a stroke is
technically caused by a dislodged piece of plaque which damages a brain
blood vessel, but ferrets have not been documented with that. Ferrets
DO throw clots, though, and that's a thrombosis (and at times a clot
will land in the brain blood vessel and block it). I don't have time
for a thorough search of both archives but you can begin with things
like this and then also seek ones on thrown clots (thrombosis):

<http://listserv.ferretmailinglist.org/SCRIPTS/WA-FERRET.EXE?A2=ind0010&L=FERRET-SEARCH&P=R41071>

>>Unfortunately, I have no experience with strokes in ferrets, nor do I
>think they have ever been documented in ferrets. In fact, I would tend
>to think that this is a misleading diagnosis which was probably not
>backed up by any definitive lab findings.
>
>Let me tell you why I am a "doubting Thomas" on this one. Many private
>practitioners tend to ascribe human diseases such as heart attacks and
>strokes to their patients as their owners tend to understand these
>diseases and the poor prognosis associated with them.
>
>Why don't ferrets have strokes and heart attacks? Because they
>generally don't have the causal diseases of hypertension and
>atherosclerosis. Ferrets don't get hardening of the arteries, they
>don't need bypasses, and they don't get myocardial infarcts (at
>least I've never seen one. The primary reason that they don't get
>atherosclerosis is that their diets are much better than ours -
>less saturated fats, less processed sugar, less sodium!
>
>We also don't see hypertension in ferrets, and that, and
>atherosclerosis, are the two main risk factors for strokes, at
>least in humans.
>
>I've looked at lots of ferret brains from animals with neurologic
>deficits, and never once seen any evidence of a stroke (which
>essentially results from rupture of a cerebral vessels and hemorrhage
>into the surrounding brain).

http://ferrethealth.org/archive/YG11338
>Regarding the theory of stroke - this is really not a problem
>in ferrets - stroke is most often seen in species with chronic
>cardiovascular disease such as atherosclerosis, such as humans
>and certain inbred species of animals, but not ferrets.

http://ferrethealth.org/archive/YG3833
>To my knowledge, strokes have never been diagnosed in ferrets - nor
>have I ever seen evidence of intracranial hemorrhages in ferrets.

http://ferrethealth.org/archive/YG2176
>Interesting - ferrets do not have strokes - strokes are a peculiarly
>human disease which is associated with atherosclerosis - a disease
>yet to be diagnosed in ferrets.

and then you can go and do more searching if needed or desired.

The reason it is important to know that is because often the reason
that the ferret threw the clot in the first place can be treated for
a while!

There is one prominent cause and few other possible causes. Heart
disease is by far the most common cause (so a heart ultrasound makes
sense when symptoms that can be caused by a thrown clot appear), but
other less common causes can be kidney disease, lymphoma, etc. The
symptoms depend on the location where the clot lands, and ones to the
brain do at times -- but not always -- heal given a long enough time
(and we have personally had one whose clot was due to kidney disease
who did recover from a very serious brain clot which had him in a coma
with him finally having minimal permanent damage after some weeks of
home PT). Whether a ferret who throws a clot is likely to throw a
second one depends on several factors including cause, how well the
cause is being treated, activity levels which are possible, and luck.

There are other neurological diseases in ferrets which can cause such
behavior, such as ADV. I've actually see a video of a ferret with ADV
moving in tight circles, so central nervous system diseases seen in
ferrets also have to be considered. BTW, that includes toxoplasmosis
but they can not pass that disease along (only cats do).

2. Larger circles only when nervous can be a repetitive behavior from
too constant and too long caging in a too small a cage. There is a
range of such cage behaviors and circling is among the most common
ones. Given the opportunity many break that habit but not all do, so
you can help break it by often lifting up the circling ferret to
distract it, then perhaps leading it somewhere with a treat before
giving the treat.

There are probably other possible behavioral causes including personal
quirks including one in which the circling just is comforting when
under stress.

Sukie (not a vet)

Recommended ferret health links:
http://pets.groups.yahoo.com/group/ferrethealth/
http://ferrethealth.org/archive/
http://www.afip.org/ferrets/index.html
http://www.miamiferret.org/
http://www.ferrethealth.msu.edu/
http://www.ferretcongress.org/
http://www.trifl.org/index.shtml
http://homepage.mac.com/sukie/sukiesferretlinks.html
all ferret topics:
http://listserv.ferretmailinglist.org/archives/ferret-search.html

"All hail the procrastinators for they shall rule the world tomorrow."
(2010, Steve Crandall)

[Posted in FML 7210]