NURSING EQUIPMENT AND CARE: SCALES: WEIGHTS
 
Perhaps the single most important and expensive piece of equipment ferret
owners should own is a scale to periodically weigh their ferret.  Buy the
BEST possible scale you can afford and do not be shocked if it runs you
more than $100.  You should look for a digital metric scale with a broad
weighing pan, the ability to tare a weight, and the ability to measure
accurately to a gram.  When weighing ferrets anything under a gram is
insignificant, however, being able to accurately report individual grams
is potentially important.
 
If you cannot afford a good digital scale, look for a cheaper spring
scale used by dieters to weigh food portions, or a good postal scale.
These scales have small weighing pans, but you can glue a plastic
container to it and it will work fine.  If the scale tips over, just
glue it or drill holes in each corner and screw it to a 12 in. by 12 in.
piece of plywood and it will be fine.  These cheaper types of scales
don't have a tare adjustment, but they generally have an adjustment screw
so you can zero the setting, which you should do before every weighing to
account for room temperature differences.  If you can't zero the setting,
pay a little more and find a different scale.
 
Even if the scale is off a bit and doesn't weigh accurately, it doesn't
matter as long as it is precise in the measurements.  In other words, it
might weigh a 100 g weight at 110 g, which means it has poor accuracy,
but if it ALWAYS weighs it at 110 g, then it has good precision.  If
the precision is good, then the relative differences in weight are
more-or-less accurate.  For example, suppose you tested your scale and
found it measures a 250 g weight at 270 g; it is off about 7.4%.  If this
scale measured a 45 g drop in your ferret's weight, it would only be off
4 to 5 g at the most.  A ferret can lose that amount of weight just going
to the bathroom, so I would consider the error relatively insignificant.
The important thing to remember is to look for short- and long-term
weight loss and weight loss patterns, NOT to get paranoid or compulsive
about small daily or seasonal shifts in weight.
 
Weigh your sick ferret EVERY day, and RECORD THE DATA!  Sudden weight
loss is often the first sign of dehydration or bleeding and a daily
weight can be an important diagnostic sign for your vet; a 2 oz weight
loss over a month would mean different things depending if the loss was
rapid or slow.  What I do is carefully lift the nest box out of the cage
and weigh it with the ferret still inside, then carefully remove the
ferret and reweigh the box, mess, bedding, toys; whatever was there when
initially weighed.  The difference in weight is the ferret provided only
the ferret was removed and any error will be insignificant.
 
One thing about weights owners need to appreciate is the concept of
"significance."  A 2 oz loss of weight in a 3 lb ferret is insignificant,
but the same loss in a 1 lb ferret is pretty profound.  As a rule of
thumb, consider a 10% loss of weight within a 3-day period significant
and you need to consult a vet immediately.  Also, it is far easier to
track differences if you use grams, but if you insist on remaining in the
Stone Age, at least count weight in ounces rather than using pounds and
ounces.  Some people have a hard time seeing a significant difference in
a 2 oz loss in a 1 lb 1 oz ferret, but seeing the loss in a 17 oz ferret,
it is easier to realize the 11.8% weight loss.  Even if you don't do the
math, it is easy to see 2 oz is greater than 1.7 oz (10% of 17 oz), a
signal of danger.  It is even easier to see the difference when noticing
a 57 g drop in a 482 g ferret; your eye can immediately pick out the
difference is more than 10%.
 
Bob C
[Posted in FML issue 4401]