There is a lot of supposition regarding modern ferret diseases.  Are
they due to caging conditions, or artificial lighting?  Are they due to
neutering?  Where they always there, but never recognized?  Are they
caused by modern breeding practices, especially those of large ferret
farms?  Are they the result of diet and/or feeding practices?  There are
dozens of other questions; all are profound, all are important, and all
lack clear resolution.
 
For the post part, these questions are moot.  Ferrets have been housed
in cages of some type or another for centuries, if not since initial
domestication (modern overcrowding may have some influence, probably in
the nature of a triggering agent).  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.  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.  Could such a visually unique illness such as adrenal disease, or
even one a subtle as insulinoma, be missed or misdiagnosed?  (Hint: scan
the FML and you will see scores of instances where someone clearly
unfamiliar with either disease clearly recognizes the problem, and
describes it well enough to be diagnosed sight-unseen).
 
That leaves the two major contenders being genetics and diet.  There is
no doubt breeding for size and fancy color can result in severe and
devastating genetic disease in ferrets.  Still, there is NO evidence
breeding for any trait has resulted in the widespread introduction of
various ferret diseases, such as insulinoma or adrenal disease, into the
ferret genome to such an extent that it is found in significant numbers
in a ferret population numbering millions.  It also cannot explain why
these diseases are beginning to show up in other countries, in breeding
populations that have not had significant gene flow from USA ferrets.
Also, if the =93Tainted USA Genetic=94 hypothesis is correct, it would
have required either a rare existing trait or a new mutation to
contaminate the genetics of a large group of breeding ferrets, not just
once, but for each disease introduced.  PLUS it would have to be done
simultaneously at a single focal point in time.  If the trait was
dominant, then MAYBE such a series of coincidences could have occurred,
but if adrenal disease was dominant, then a predictable number of
offspring would contract the disease, something clearly not occurring
in the USA population.  Nor does the hypothesis account for the large
numbers of ferrets being imported for breeding purposes, the tendency to
back-breed to polecats, or even the fact that the incidence of disease
does not result in the type of mathematical ratios (sick to ill) expected
in a population of millions.  There is no doubt genetics is involved, but
it is unlikely inbreeding causes the problem we see with ailments like
insulinoma and adrenal disease.
 
Finally, there is diet, which is why we are here.  The dietary
restriction paradigm can explain the types of diseases, why they are
hitting at specific ages, and why they impact specific organ systems.
But, even this question is moot if we cannot show some type of increase
in modern populations compared to historic ones.  So, the question of
the century is, is diet and/or dietary practices causing the relatively
sudden onset of various ferret diseases?  Before we can answer that, we
have to know if the "sudden onset of various ferret diseases" a real
phenomenon, or just an epiphenomenon of the computer age.
 
Bob C
[Posted in FML issue 3966]