The last post left off with my telling you about a bit of the history of
adrenal disease. I want to be clear on this; just because something is not
mentioned in a reference or it is not diagnosed by veterinarians, it doesn't
mean it isn't there. For example, sometime ago I was interested in canine
distemper and was looking through the old literature and found very little.
However, when I started looking for the sweats, I found a tremendous amount.
Just because I couldn't find old references to adrenal disease doesn't mean
some are not there. On the other hand, using old documents for an
information search is a tried and true part of archaeology; these old
records are called ethnologies, and an archaeological report without some
reference to one is hard to come by. I have done a similar thing with
ferrets to build an ethographic reference. I've read about every ferret
book published (the first dates to 1790), put the data concerning disease,
life span, weights, reproductive age, etc., into tables and gandered at the
results.
What I found is, the ferrets about a hundred years ago are about the same as
those today in terms of life spans (6-8 years), body weight, diseases,
reproductive cycles, and litter size. Knowing that the quality of diet is
very important to the reproductive status, I specifically looked to see if
the ferrets were breeding at a year old or older. A good, high-quality diet
assures the first, but any mustelid that is nutritionally stressed will
delay reproduction until the second year, either by not coming into
heat/rut, or by absorption of the embryos. Almost all accounts had ferrets
breeding at one year of age, with litters averaging 4-8 kits. You can't
expect better today, with all our vast knowledge and vet care. In every
field I looked, I found the descriptions from the past to fit exactly in
with today's data. (I do feel the average age at death was lower,
indicating more ferrets died earlier, but the ranges were the same) To me,
this means people treated the ferrets quite well and were concerned with
diet and health. Therefore, I feel the assumption that adrenal disease was
uncommon a hundred years ago is safe to make. If they didn't know that was
causing it, they would have at least mentioned the symptoms.
I am convinced that the proportional differences in adrenal disease rates
between the Old and New Worlds have more to do with environmental factors
than genetics. I'm not implying genetics is not important, for I actually
feel ferrets as a "group" are prone to them. I just feel various
environmental factors are also important, and an understanding of what is
different between the two groups is in order.
Food: The USA/Canada primarily feed dry kibbled foods; while such foods are
being accepted in other countries, pullets, carcass parts and raw meat
products are still commonly given. Think about this; as far as I can
reconstruct, ferrets in the USA had a low incidence of *reported* adrenal
disease until the late 1970s. Now, this might be coincident with better
veterinarian diagnoses, more treatment of ill ferrets, or the widespread
introduction of dry kibbled foods, which took place at about the same time.
A possible problems are are a shift from foods having lots of fiber (fur)
and roughage to eating something that comes out like paste.
I *have* to get off track just a moment here. I just read Fox etal 1997
paper on Helicobacter. A superb paper and one that left me wondering out
loud if some of the problems we are recently having with recurrent bowel
inflamatory disease, ECE and the like might be tied to expecting our little
fursharks to push their intestinal toxins out the back using paste rather
than fur and fiber. It is only a recent discovery that human bowel cancers
are tied to fiber content. Kibbled foods are essentially a paste made of
finely ground foodstuffs; a vole has fur, bone bits, teeth, and non-digested
parts pushing the nasties through. Some recent research has shown dogs and
cats are generally healthier with fewer down days when fed a more natural
diet. Aside over.
Feeding: Here we generally feed ad libatium; that is, we leave food in a
dish and the dish with the ferrets at all times. This is in part because
someone once erroneously equated a high metabolic rate and food requirements
to mean they have to eat all the time. This is not only untrue in healthy
ferrets, but it would be impossible to do in the wild. What do you think
fat is for? Ferrets do just fine if fed twice a day, and will adjust their
eating habits accordingly. There are some very nasty little papers that
suggest animals eating ad lib have fatter bodies and shorter lives that
animals on a bidaily diet, which has been a traditional practice in most
other places ferrets are kept.
Living Environment: In the USA/Canada, ferrets are house pets and are rarely
taken into the out-of-doors. Most other places house ferrets outside and
they are rarely taken indoors.
Photoperiodism: In the USA/Canada, indoor ferrets are constantly exposed to
unnatural light periods. I remain unconvinced that full-spectrum light is
any different than the ol' tungsten lamps, since the latter has been used
for decades to control photoperiodic cycles in both birds and mammals, but I
am concerned about the photoperiod cycle in general in modern environments.
This isn't a problem for ferrets housed outside.
Trace Nutrients: No one can tell you exactly what trace nutrients human
beings need, and we have been spending billions to find out. Very little
time or effort has been spend on discovering the essential trace nutrients
for ferrets. Remember, ferrets were domesticated from polecats, who evolved
as primary carnivores eating fresh meat on a frequent basis. In a cosmic
blink of an eye, they have shifted from eating carcasses to eated dried up
bits of preground paste.
Exercise: Ever try to work out in closet? Need I say more?
Inactivity: Inactivity is mostly due to boredom rather than small cages.
I've included boredom because all systems of the ferret are affected,
including the endocrine system. Bored animals and people have been shown to
have higher disease and death rates. It might take awhile, but you can be
bored to death. Continued in the next post.
Bob C and 20 MO Furrbutts
[Posted in FML issue 2220]
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