Personal opinion coming.  From what I've learned talking to animal
nutritionists and veterinarians I'm not sure I'd recommend a diet consisting
of Purina Cat and Kitten Chows and Whiskas.  They quality of the protien in
these foods is not right for ferrets.  Their digestive tracts are shorter
than cats and are incapable of digesting vegetable protiens.  The cited
article in question admitted this as well.  To get the same amount of
nutrition from the lesser quality foods requires more food negating perhaps
all of the cost savings.  PUrina has several foods of varying quality.
Their Mazuri Ferret Diet and ProPlan formulas are better than the Cat and
Kitten Chows.  They also cost less than the possibly even better Totally
Ferret, Marshall and 8in1 diets.  We can not recommend the grocery store cat
foods for ferrets.  We doubt they are cost efficient nor nutritionally sound
for ferrets.  Remember ferrets are not cats; these foods were developed for
cats.
 
Other points in the mentioned article I'm not sure I agree on are...
 
Based on information I've gotten from vets:
Ethoxyquin has not to my knowledge been proven as a carcinogen.  Rancid fat
is more likely to be a problem than the preservative.
 
Based on information I've gotten:
Dry kibbled pet food is better in some regards than other foods but
convinience of the owners is its primary advantage.  It is a very easy way
to achieve a balance of the nutrients needed but has disadvantages over a
more natural meat type of food.  Kibbles cause excessive wear on animal
teeth.  Prepared foods tend to lead to more tartar than 'raw meat' in
carnivores.  Bones are useful in a ferrets diet.  Not sure where a
genetically similar polecat would get fillet of rodent.  From what I've
learned and observed, bones (especially the marrow inside) are good for
ferrets.
 
Asking BIG's pet peeve:
Can anybody cite where chocolate is toxic to ferrets?
 
bill and diane killian
zen and the art of ferrets
 
[Moderator's note: I think a lot of people think the big E causes cancer,
because, after all, what else do chemicals in food do?  Actually, ethoxyquin
is an anti-oxidant, and as many antioxidants are prone to do, there are
studies which show it actually has an inhibitory effect on cancers.  That's
not to say that it's all-good: I don't doubt that some ferrets might have a
reaction to it - allergies exist in ferrets as well - but all-in-all it
seems to cause no problem for most, and rancid fats are indeed a problem as
you mention.
 
There is yet another reference to chocolate later in this issue.  I've
searched for studies and haven't found any - I again will be pleased if
someone can offer more info.  There was some discussion on a veterinary list
last month where someone quoted a toxic dose of theobromine in rats.  It was
a pretty high dose, if I recall, plus it was a DAILY dose, implying the
quoted dose was an average long term daily dose rats could deal with it.  If
anything, this strengthened my long-standing opinion the chocolate used as a
treat is not harmful to ferrets.  BIG]
[Posted in FML issue 1460]