Having gotten a note asking how much A to give...

It says the amounts used in the study in both the abstract given and
in the article. An amount found to protect well is in both. In the
abstract given, notice on re-reading:

BEGIN QUOTE
In contrast, control ferrets that were given 30 mg of vitamin A did
not develop typical distemper after infection and exhibited only a
mild rash. The supplement did not negatively affect ferret health and
resulted in a 100% increase in serum and liver vitamin A concentrations.
END QUOTE

Vitamin A is less likely to be ingested at toxic levels by ferrets than
by humans, with ferrets preadapted to higher doses by being descended
from animals who ate livers pretty well each day. Humans don't have
that sort of ancestry so for us A is easier to overdose. On the other
hand it pretty hard to overdose D for humans -- actually most people
don't get enough -- and we are descended from ancestors who got a lot
of sunlight exposure. Ferrets, on the other hand, are descended from
ancestors who had crepuscular (dawn and dusk) optimal activity and
lived in burrows so can develop hypercalcemia if they get too much D.

See below and in the links given as well as in the FHL Archives which
are very easy to use for more info, please.

> J Nutr. 2007 Aug;137(8):1916-22.
>Disease manifestations of canine distemper virus infection in ferrets
>are modulated by vitamin A status.
>Rodeheffer C, von Messling V, Milot S, Lepine F, Manges AR, Ward BJ.
>McGill University Health Centre Research Institute, Faculty of
>Medicine, Division of Infectious Diseases, Montreal General Hospital,
>Montreal, QC, Canada.
>
>The measles virus (MV) causes half a million childhood deaths
>annually. Vitamin A supplements significantly reduce measles-
>associated mortality and morbidity. The mechanisms whereby vitamin A
>acts against MV are not understood and currently there is no
>satisfactory small animal model for MV infection. We report on the
>development of a ferret model to study antiviral activity of vitamin A
>against canine distemper virus (CDV). CDV is closely related to MV at
>the molecular level and distemper in ferrets mimics measles in humans.
>We infected vitamin A-replete (control) and vitamin A- depleted
>ferrets with CDV and assessed the ability of high-dose vitamin A
>supplements to influence CDV disease. In control ferrets, CDV
>infection caused fever, rash, conjunctivitis, cough, coryza, and
>diarrhea. In contrast, control ferrets that were given 30 mg of
>vitamin A did not develop typical distemper after infection and
>exhibited only a mild rash. The supplement did not negatively affect
>ferret health and resulted in a 100% increase in serum and liver
>vitamin A concentrations. We also found that profound vitamin A
>deficiency is inducible in ferrets and can be rapidly reversed upon
>high-dose vitamin A supplementation. Vitamin A deficiency caused
>anorexia, diarrhea, cataracts, behavioral abnormalities, and
>ultimately death, with or without CDV infection. All ferrets that
>received vitamin A supplements, however, recovered uneventfully
>from CDV infection. These results replicate many aspects of the
>observations of vitamin A therapy in humans with measles and suggest
>that CDV infection in ferrets is an appropriate model for the study
>of the antiviral mechanism of vitamin A.
>
>PMID: 17634264

The full article is HERE:
http://jn.nutrition.org/cgi/reprint/137/8/1916

The FML Archives are here (and in the header of every day's FML):
http://listserv.ferretmailinglist.org/archives/ferret-search.html

The FHL Archives are here (and linked to from the FHL homepage):
http://ferrethealth.org/archive/

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

[Posted in FML 6412]