From:
sukie crandall
Date: 2005-07-19 17:13:39 UTC
Subject: RE: [ferrethealth] Dealing with an older ferret Oils
To: ferrethealth@smartgroups.com
Message-id: <4D3DE723-3BE2-4FCB-B537-87DC5FF04A33@optonline.net>
Messages by vets and actual veterinary nutritionists on the topic of
Vitamin A are rare in the Archives:
http://fhl.sonic-weasel.org/browse.php?msg=YG3053
doesn't answer anything but is by someone who not only has done
advanced study but whose doctorate is in one of the right tcategories
to be most informed
This vet post is from 2001 and from Bruce Williams who is one of the
best veterinary pathologists out there for ferret pathology
information (BTW the voiced concerns in the general ferret community
about levels of Vitamin A became ingrained much earlier than 2001.)
http://fhl.sonic-weasel.org/browse.php?msg=YG643
which reads:
START QUOTE
> Vitamin A toxicity has yet to be documented in ferrets, so it is
> tough to say exactly what you would see. In cats, where we see most
> cases, bony lesions, especially of the neck. Cervical spondylosis
> progressing up to fusion of the joints in the neck, and to a lesser
> extent the limbs can be seen. Most cases of Vitamin A toxicosis
> arise from cats eating bovine liver, as the liver is where Vitamin A
> is stored.
>
> Vitamin A toxicosis has also been seen in feedlot cattle fed diets in
> which excessive levels of Vit A were added. An interesting lesion in
> these animals was blindness, as extra bone was laid down around the
> optic foramen, through which the optic nerves pass.
>
> I suppose that prolonged feeding of liver may cause this lesion in
> ferrets, or the feeding of EXCESSIVE amounts of linatone. However,
> the quanitities required to cause this would probably result in
> severe diarrhea due to the oil content before a significant risk of
> Vitamin A occurred.
END QUOTE
In the below URLs is a hypothesis -- by Bob Church whose education is
in first biology and then comparative osteology for archeological
applications (not in nutrition though some aspects of that affect
bone formation and destruction, nor in veterinary medicine) and whose
food posts tend to be widely read and popular -- that many ferrets
today might actually have less Vitamin A in them than they need. It
IS A HYPOTHESIS ONLY, and I include it just to illustrate that when
it comes to nutrition there is great deal still unknown, and more so
in ferrets than in humans, so don't panic about hypotheses (in any
direction):
http://fhl.sonic-weasel.org/browse.php?msg=YG14166
There is also a latter grouping by the same author in SG253-4, and SG
257-61 going into this possibility in more detail. Note that these
are hypothetical. All sorts of problems arise when people mistakenly
assume hypotheses are equal to proven facts. Note, too, that many of
the fearful things on assorted websites about what *might* be too
much Vitamin A for ferrets all too commonly tend themselves to be
based upon hypotheses about levels of A in ferrets, but with people
forgetting that they were dealing with hypotheses.
As has been pointed out in past here, "not documented is not the same
as not existent" and certainly it may turn out that some of the
nutrients in supplements could go higher while others could go lower,
so poor health associated with megadosing supplements may be related
to A, or to other vitamins or to one or more of the minerals.
I guess my main point is that as far as I know nothing is written in
stone on this score, so we each should make our own best personal
choses based upon what is currently known or guessed (and hopefully
knowing the differences) while realizing that with more information
recommendations will change over time (just as some researchers into
human nutrition are now wondering if perhaps the recommended levels
of Vitamin E for humans may be too low).
-- Sukie (not a vet)
Ferret Health List
http://www.smartgroups.com/groups/ferrethealth
FHL Archives
http://fhl.sonic-weasel.org
International Ferret Congress
http://www.ferretcongress.org