Message Number: YG4687 | New FHL Archives Search
From: RRC
Date: 2001-06-19 08:10:00 UTC
Subject: Re: Ferrets and fat

Sidsel L. Espersen wrote:

>Does our pet ferrets need less fat than wild or pelt ferrets?
>This sounds like rubbish to me, but the Danish Ferret Association claims
>that this is the away to go, and a new danish ferretfood has been designed
>to fit this. I've taken one look at that food, and that as well as the claim
>seems to be rubbish. Grain as the first ingredient, only 6% chicken then
>some fish and then follows a lot of not so good stuff.
>I was also shocked to learn that the Danish Ferret Association claims that
>there are no "experts" on ferret nutrition (sp!?) - and I thought of Bob
>Church and his diet posts and it said nothing about less fat and more

First, domestication has NOT changed the ferret's nutritional needs.
There is NO evidence for this, anywhere. I would reject that hypothesis
without first having a tremendous amount of peer-reviewed support. I
consider the ferret's nutritional needs to be essentially those of wild
polecats, and I can't think of a single report which suggests otherwise.
If I were you, I would demand your organization produce verifiable
documentation, including peer-reviewed journal articles, to support such
a claim.

I would consider Totally Ferret's Dr. Willard (who occasionally posts
here) to be a ferret nutritional expert. I can't be sure, but I doubt if
many people from ANY country knows as much about ferret nutrition as he
does. As a zooarchaeologist who tries to use recovered animals bones to
determine prehistoric human nutrition, I have been forced to spend
several years delving into the subject (I actually put my program on a
two year hiatus until I could get through advanced studies in
biochemistry and nutrition). Still, Dr. Willard has SPECIFIC knowledge
about ferrets, including studies I am not privy to, and I consider his
experience and knowledge to be superior to mine.

Ferrets get seasonally fat, starting in mid to late summer. This is an
evolutionary adaptation to help polecats through harsh winters when prey
species are hard to find. The domesticated ferret simply inherited the
trait. Not all domesticated ferrets get as fat as others during this
period, which is also natural and nothing to worry about. If your ferret
becomes seasonally fat, there is not a lot you can do about it, and
trying to prevent it may result in negative impacts on the ferret's
health. It's a natural thing for them, and there is no need to try and
prevent it.

Older ferrets tend to put on some pounds as they become less active.
From my experience, it is self-limiting, and in a reasonable amount of
time, the ferret learns to adjust their eating habits (or they simply
lose their appetite), and while the fat may not completely drop off, it
doesn't get any worse either. I don't personally worry about this
because I figure the extra ounces are a sort of buffer to protect the
ferret during illness when the appetite might be suppressed.

On the other hand, *I* have seen a tremendous number of obese ferrets
which I attribute to three factors: constant feeding, caging and lack of
exercise, and increased calories from grain products in commercial
foods. There is a modern mythology which states ferrets have to have a
constant supply of food to remain healthy. That is pure rot! That may be
true with a SICK ferret, but healthy ones are fully capable of adjusting
their sleep and activity cycles to take advantage of periodic feedings.
There have been a number of studies which have shown animals (rats,
dogs, cats, mice, humans) who have unlimited access to food have SHORTER
lives! I am not sure where this modern feeding mythology has sprouted,
but it sure ignores the natural history of the ferret, as well as the
published historical literature. Nearly every historic ferret care book
suggests a couple of feedings per day, which is about how many times a
day polecats eat. Those ferret farms a hundred years ago may not have
had all our modern veterinary medicine, nutrition and knowledge, BUT
they had breeding rates nearly as high as modern ferret farms, and the
ability to breed has long been seen as an indice of nutritional health.
MOST of them only fed their ferrets twice a day. I have read many
comments on ferret lists suggesting polecats cache food so they will
always have something to eat, which is correct in terms of having a
larder to go to when food is hard to find, but it has nothing to do with
the number of times per day a polecat (or ferret) will normally eat. In
other words, polecats (and ferrets) cache food to insure TOMORROW'S
meals, not because they "need" to eat 6 or 7 times TODAY. As long as the
food meets a healthy ferret's caloric and nutritional needs, just a
couple of feedings per day are fine (and is actually all a ferret really
eats if the food is good and nutritious).

This becomes especially important when a ferret has periods of enforced
inactivity, which occurs because of caging. Caging, even if required, is
not a natural nor normal aspect of animal's lives, and it affects
everything from muscle tone, to behavior to mental health. Many modern
studies suggest actual intelligence is directly related to sensory
input, so those individuals who have lowered sensory inputs will have
lower intelligence (Smart animals come from environments which stimulate
the mind, increasing connections in the brain). Caging also impacts
visual focusing length; even astronauts have found a few weeks in space,
where everything inside the shuttle or space station is a limited
distance from the eyes, causes the lens and muscles to adapt to that
distance (this observation is being used to explain why so many people
require glasses; the surge in diagnosed short-sightedness may be related
to limited distances for reading, television and computers). Caging has
a direct influence on ferret behavior; first, it prevents normal
behavior by restraining animals in a single location, and second, it can
frustrate ferrets and/or induce tremendous boredom. A part of those
abnormal behaviors include eating in excess of caloric needs, and/or
eating inappropriate foods (cloth, rubber, whatever). The worst aspect
of sustained caging is simply a lack of exercise. Ferrets eat to met
caloric need, which means those ferrets that work hard will eat more
than ferrets that hardly work. The problem is, a food which meets
caloric needs before they met nutritional requirements (you see this
with many cat foods) will not result in proper ferret nutrition. But
ferrets (like all mammals) have a sort of self-correction program which
stimulates eating when nutrition is poor. You may have had a craving for
a food when ill, dieting or pregnant, so you know how this works. If
their only choice is the poor food in front of them, they can overeat
(or resort to pica) in an attempt to meet nutritional, rather than
caloric needs. The excess calories are converted to fat and stored in
the mesenteries which support the gut, around lymph nodes, in the lower
abdomen between the legs, in the tail, and along the back, especially
over the rump area. Also, a lack of exercise produces poor muscle tone,
which further reduces activity, leading to a cycle of obesity. I have
been generally able to trace the obesity I've seen in ferrets to lack of
exercise (some ferrets LOOK fat, but are actually suffering from other
ailments. You should always consult with a vet prior to putting your
ferret on a diet of any type). Remember, the single secret ingredient to
ANY successful diet is exercise.

Ferrets are obligate, primary carnivores who produce most of their
caloric needs by metabolizing fat and protein, NOT from breaking down
carbohydrates (they can and do obtain calories this way, but several
studies have shown ferrets have little need to consume even small
amounts of carbohydrates to remain healthy). Calories in fats are super
concentrated compared to carbohydrates, so a ferret doesn't need to eat
as many fats to get the same amount of calories as eating processed
grains. But there is one important difference; when carbohydrates break
down, they are turned into sugars which result in pancreatic and other
metabolic responses. When fats or proteins are metabolized, the
pancreatic response is not as pronounced. This may or may not have
anything to do with pancreatic disease in the ferret, although I have
hypothesized it does. While glycogenesis from proteins cause health
problems in humans (the so-called "rabbit starvation" or
ketoneacidosis), ferrets—being primary, obligate carnivores—have enzymes
and metabolic pathways which prevent such problems. Several studies have
shown ferrets have no health problems at all from meeting their caloric
needs using protein.

If *I* was designing a food for a ferret, I would NEVER drop the fat
content while raising the carbohydrates. Ferrets don't need fats JUST
for calories; they also have a good list of essential fatty acids which
are required to maintain proper health (not even considering the
essential fat-soluble vitamins found in fats). Carbohydrates do NOT
supply those requirements! One reason I recommend using Totally Ferret
is because I have found it to have what seems to me to be a minimal
amount of carbohydrates. You simply cannot make a kibbled or expanded
dry food without using some sort of starchy carbohydrate, and I have
found many cat foods (and ferret foods) are half carbohydrate, and some
significantly more! While I am not sure of the exact percentage of
carbohydrates in Totally Ferret (products are listed in order of "there
is more A than B, and more B than C" rather than there is 40% A, 39% B,
10% C), and you cannot determine specific ingredient percentages from
the protein, fat and ash contents, I am convinced Totally Ferret uses
what must be close to the minimum required carbohydrate to manufacture
the product.

Personally, I think any obesity problem not tied to a health problem is
cured with adequate exercise, and I would suggest people with fat
ferrets do something to increase activity rather than monkey around with
food ingredients. Humans can diet fairly safely because we have such
large stores of nutrients in our tissues; a luxury ferrets do not
possess. If all you want to do is lower available calories, I would
never recommend reducing fats when a better solution is to reduce the
numbers of carbohydrates, which only turn into sugars. Additionally,
since reducing calories is ultimately a form of dieting, and ferrets
have limited stores of nutrients in their tissues, I would only proceed
under a veterinarian's close supervision.

These are my opinions and others may differ. I welcome serious debate on
the subject and do not hold my convictions so close as to confuse
learning with being stupid. As Ben Franklin once said, "I have not made
a mistake. I have simply discovered 10,000 ways it doesn't work."

Bob C