SCALES: FOOD AND WATER INTAKE:
 
If the scales can be used to measure urinary output, they can also be
used to check if the ferret is drinking water or consuming food.  Water
bottles are fine, but how can you tell if the ferret is drinking anything
unless you actually observe it?  Can you sit by the cage 24/7 and count
the number of licks on the bottle stem or bits of kibble missing?  When
vets ask if the ferret is drinking or eating, the best they can hope for
is the ferret owner mumbling something about having seen them at the
water bottle and food dish--hardly accurate.
 
However, with your scale at hand, all you have to do is fill the water
bottle or bowl with water, and take a weight.  Two or three times a day,
simply take a new weight, and the difference is a combination of fluids
consumed, drips, and evaporation.  Keeping in mind 1 cc of water = 1 g,
if you are missing 4 g of water, then you know 4 cc of fluids have been
utilized.  So, what part of that sum is the portion the ferret managed
to get inside them?
 
Well, the truth is, you don't really have to know as long as the bottle
isn't excessively dripping, so keep it filled and watch the drip bowl for
moisture (if water is pooling in the dish, it shows excessive dripping).
Controlling for evaporation and drips can be easily done, but do you
really need to do so?  In most cases, the answer is no.  What you are
looking for in terms of fluid intake is patterns and trends.  Is the
ferret drinking water on a regular basis?  Is the volume of water
consumed increasing or decreasing, all other factors being more-or-less
equal?  Does it significantly change over a week or so?  For these types
of data, you can subsume things like drips and evaporation into an "error
constant" and ignore them, assuming they are fundamentally the same from
day to day, AS LONG AS THE DRIPS FROM THE BOTTLE ARE NOT EXCESSIVE.  If
the drips ARE excessive, dump the bottle and buy a new one, or start
using a water dish.
 
While in most cases knowing the evaporation and drip loss value is
absolutely unnecessary, if your ferret is suffering from serious kidney
disease or some other aliment where knowing the amount of fluid intake
has real veterinary value, I would recommend figuring out the evaporation
and drip "constant" for your water set-up.  Simply set up the water like
you would for a sick ferret, and measure the difference in weight over
several days--the more days tested the better.  Top off the bottle each
day AFTER weighing.  An average will give you a great idea of what is
being normally lost from drips and evaporation, and you can use the
figure to adjust your water-use findings accordingly.  All you do is
divide that amount by the fraction of a 24-hour day you take your water
weights.  If every 4 hours, divide the evaporation and drip "constant" by
6 (4/24 = 1/6) and subtract from the water-use figure; if every 8 hours,
divide by 3 (8/24 = 1/3) and subtract.  For example, if you lose 3 g of
water per 24-hours, and you noticed your ferret utilized 4 g of water in
8 hrs, divide 3 g by 3, and subtract the 1 g result from the 4 g used;
your ferret drank 3 g of water, or 3 cc.
 
Scales are a wonderful way to make sure your ferret is eating food.
Simply weigh the bowl of food, and reweigh it later to see how much is
missing.  If you know how much a given volume of kibble weighs, say in a
teaspoon, then you know how much food the ferret ate.  It is that simple.
You do have to worry about spilled food and snacks hidden for later, but
in a hospital cage with a cardboard floor and a plastic nesting box,
finding those missing pieces is a snap.  Weighing liquid foods, such as
baby food, is much better way to determine ACTUAL intake (3 g), rather
than the perception of intake (8 licks).  In these foods, the amount of
water mixed in the food can skew results.  You can use a syringe to
measure out an actual cc (or ml) of volume and weigh it to figure out a
grams-per-cc measurement so it is easier to control for moisture, but I
am not sure that is necessary in most cases and it would be a case of
overkill.  All you really want to know is that your ferret is eating
regularly a known quantity of food.  The important point to keep in mind
is that liquid food contains moisture and will drive down the amount of
water the ferret will drink, so don't get paranoid about little water
intake when feeding your ferret liquid foods; if the urine output is
good, they are probably getting enough in the food.
 
Indeed, in most cases vets are only concerned about knowing if the
ferret is eating or drinking and the actual volumes of food and water
consumption are not that important, and I agree.  However, taking these
measurements only costs a few minutes of time, and it gives you a
wonderful tool for watching food and water intake patterns in your ferret
that could aid their ultimate recovery.  Human doctors are extremely
concerned about these values, especially in premature infants (a great
analog for sick ferrets), but vets never ask for them because, frankly,
how many ferret owners can supply the answer?  Imagine the tools you are
giving your vet when you go in and show them the ferret's food intake is
decreasing, water intake is increasing, and urine output has slowed to a
fraction of the usual!  THAT is the value of this data, NOT the knowledge
of the actual number of grams consumed by the ferret (although you can
only generate this type of data by taking accurate measurements).  In
other words, while you are making as accurate measurements as possible
of food and water ingestion, all you are really concerned about is the
general pattern and trend of intake.  Make sure you record the data as
you take the measurements.
 
Bob C
[Posted in FML issue 4402]