From:
sukiec@optonline.net
Date: 2005-07-19 21:25:31 UTC
Subject: RE: [ferrethealth] Dealing with an older ferret
To: ferrethealth@smartgroups.com
Message-ID: <5572563.1121808331201.JavaMail.root@thallium.smartgroups.com>
Author wrote:
> > There are very few reports of even *possible* Vitamin A toxicity in
> ferrets. <
> All the trouble we had was due to feeding large amounts of raw deer
> liver. Chris.
Certainly, liver is high in A.
What symptoms were there, Chris? Bone loss? Visual problems?
I finally got my brain in gear enough today to think of beginning to my texts. (Duh! Slapping my addled forehead!) In _Biology and Diseases of the Ferret, 2nd edition_ page 156 (1998) it mentions that toxicity (hypervitaminosis A) hadn't been observed and that included pregnant females fed up to 4200 IU Vitamin A/kg or body weight daily.
Too little A was documented then, though, with growth failure, night blindness, muscular incoordination (esp. of rear quarters -- as happens with so many other things in ferrets). Eye lenses may become opaque and conjunctivae encrusted, Metaplasia of epithelial tissues and fatty infiltration of the liver had been seen.
A few pages later is a section on ferrets as a model for Carotene uptake and use which is a related topic.
In _Ferrets, Rabbits, and Rodents, Clinical Medicine and Surgery, second edition_, page 444 (2004) the amount of A needed by ferrets is treated as an unknown (no amount given).
I don't have my other two vet texts handy to look in them, but the latter of the two above is the most recent such text that i have, and the the first is the one which goes into dietary ills in the most detail.