Bob Church has now twice suggested that the only relevant factor in
the perceived recent increase in diseases such as adrenal, insulinoma,
cardiomyopathy, etc, is diet, specifically an ad lib diet.  He dismisses
factors such as lighting, altering, genetics, and so on, saying these
factors have not changed significantly over the history of human-ferret
interaction.
 
I disagree.
 
>Artificial lighting appears a viable hypothesis, except that ferrets had
>been housed in electrified barns and ferret sheds for most of the last
>century, especially in the USA.
 
I know Bob has studied the history of the ferret farms in the early
part of the 20th century.  I live quite close to an area where tens
of thousands of ferrets were raised in barns, sheds and outdoor pens.
While some barns in those days may have had electricity, it seems to
me unlikely it was anything more than a bare bulb or two that provided
enough light for the farmer to feed and water his stock during the winter
months.  It was very different I suspect, from the bright lighting 14-16
hours in most homes today.
 
These ferrets probably also had nesting boxes to provide additional
darkness, and of course were not neutered.
 
(Sidenote: A recent study of women who worked night shifts (and therefore
were exposed to more light and less dark) showed an increase in
endometriosis, a proliferation of uterus lining cells in places where
they shouldn't be.  Endometriosis is frequently treated with Lupron.
Just one of those "Hmmm interesting" things.)
 
>There is a curious lack of correlation of disease caused by early
>neutering in ferrets to similar problems in other animals also neutered
>at a young age.
 
I'm not a zoologist, so my experienced here is limited.  But what other
animal is systematically, routinely and almost universally altered at
such an early age?  Dogs and cats are more often altered now than in the
past, but usually not until they have reached adult size, and not before
a normal weaning age when their eyes are barely open.  Male horses are
gelded, and cattle neutered, but again not in infancy.  It is interesting
to note that none of these animals have light/dark controlled
reproductive cycles.  Are there others more similar to ferrets?
 
Combining the early altering with the abnormal lighting surely could have
profound effects on a ferret's endocrine system.
 
Diet is of course also an important issue, and the ferret's diet (and
how it is provided) has also changed over the last few decades.
Interestingly, Bob himself has pointed out that the bread/milk diet is
very similar in overall protein/fat/carbohydrate levels to kibble.  But
it is true that a constantly available food source is a new factor for
ferrets.  (By the way, did diseases in dogs and cats increase when kibble
became more popular than canned food for them?)
 
So ALL these factors, including others such as inbreeding for fancy
colors, possible exposures to environmental toxins, etc, HAVE
fundamentally changed over the last few decades for ferrets in the US.
 
Bob suggests that Occam's Razor should lead us to select the simplest
explanation, which he says is the ad lib diet.
 
Unfortunately, biological systems are ALWAYS complex systems that rarely
yield to simple explanations.  I remember a few decades ago when there
was hope for "A Cure for Cancer".  No one expects that anymore.  We
realize now that cancer is not one disease, it is a multitude of
conditions, each of which has its own causes, contributing factors,
genetic predispositions, environmental factors, life style effects, etc.
There is no single cause, no simple cure, no magic bullet.
 
I fear there will be no simple solution for ferrets either.  It is
unlikely that all these diseases have a single cause, a single cure.
 
But in the meantime, I look forward to hearing Bob's recommendations on
feeding practices.  I cover my ferrets cage with a heavy dark cloth, give
them lots of dark sleeping spots, try to improve their diet, and let my 2
youngest girls go through a heat cycle before spaying.  Will any of it
help?  I don't know, but it's all I know to do for now.
 
Linda Iroff
Oberlin OH
[Posted in FML issue 3967]