NURSING EQUIPMENT AND CARE: SCALES: URINE OUTPUT:
 
Another really good function of a scale, which few vets mention and even
fewer ferret owners consider, is the weighing of pee to get a handle on
urine output.  If you have a ferret with kidney or heart problems, has a
urinary blockage, ascites, or has been suffering from extreme diarrhea,
it is valuable to know how much urine they are excreting so you can
better determine how many fluids to give, if they are blocked, or if they
are becoming dehydrated.  The problem is, a ferret won't pee in a cup for
you, so how do you measure the fluid?  It's easy, and if you follow these
directions with care, you can make a fairly accurate determination.
 
First, use a clean litter box, and ADD ZERO, ZIP ZILCH litter -- use it
empty!  To entice the ferret to use the empty box, just smear a little
poop around the edge of the wall, and they should use it well enough.
After the ferret has used the box, lift one end so the urine will drain
to the other side.  While that is happening, carefully weigh a 6 in.
square piece of paper towel (if your scale as a tare function, you can
tare it to zero).  Once you know the weight of the paper, use it to soak
up the urine, making sure you get all there is to get.  If the paper
is too small to get all of it, cut another small piece and record its
weight, and then soak up the remaining urine.  You could try pouring the
urine into a measuring device, but small droplets are always left behind,
and the smaller the volume of urine output, the more important those tiny
little drops are to the total.  The paper towels will get all of them, so
it is more accurate in the small volumes leaked out by ferrets.
 
Weigh the urine-soaked paper, and the difference between the dry toweling
and the wet toweling is the weight of the urine.  As it turns out, a
cubic centimeter (or 1 ml) of pure water weighs a gram.  Normal urine has
a specific gravity ranging from 1.002 to 1.028, meaning it is a tiny bit
denser than water.  It also means it only weighs a few hundredths of a
gram per cc more than water, so for our purposes--and in the volumes we
are measuring--we can consider a cc of urine to weigh a gram.  You can
test this to see for yourself; weigh a tablespoon of water and compare
it to a tablespoon of urine, and the difference is so small most home
scales cannot detect it.  So we can consider a 3 g weighed measurement
to mean the ferret has voided about 3 cc of urine.  This is not without
precedent; maternity nurses weigh diapers to measure baby urine at
1 cc = 1 g, and operating room nurses weigh gauze sponges to measure
blood loss, so the technique is sound.
 
The value of this data is that we can use our scale NOT JUST to watch
body weight, but also to watch for trends in urination.  If a male ferret
voids roughly 3 cc each time they pee, then if they suddenly start only
putting out 1 cc at a time, it could be a sign of danger (assuming they
are drinking normally).  Or, if they are drinking normally, but suddenly
start putting out more pee than typical, it is time to discuss the change
with a vet.  Perhaps the urine output was 3 cc one day, 2 cc the next,
and 1 cc the third; great data if you suspect kidney problems or chronic
dehydration.  This is exactly the type of data your vet would love to see
when evaluating a sick animal!  Oh yeah, RECORD YOUR DATA!!  (did I say
that before?)
 
Bob C
[Posted in FML issue 4401]