Clear urine is not necessarily a problem - in fact, it rarely is.  The
color or the density of the yellow in urine is a result of the hydration
status of the ferret at any one point in time.  It's very much like your
own urine - if you have had a lot of water to drink, your urine will be
very dilute, almost clear, and there will be a lot of it - your body is
releasing a lot water.  If you haven't had a lot of water, and it is a
hot day, then your kidneys will conserve water, and the urine that you
pass will be be dark yellow - very concentrated.
 
In most cases, a ferret's dilute urine simply reflects an abundance
of fluid in the body that can be released.  There are, however, some
conditions that may result in excessive release of fluid - chronic renal
disease (in which the kidney cannot conserve urine), chronic steroid use -
(steroids inhibit the chemicals that assist the kidney in conserving
fluid), and diabetes mellitus (excess sugar in the urine results in
"drawing" fluid out of the body).  (There are some others, but these
are rare enough in ferrets to be eminently forgettable.)
 
The bottom line is - if you are concerned - a routine bloodwork and
urinalysis will easily tell if there is really a problem, or if clear u
rine is appropriate in your ferret for this particular moment in time.
 
With kindest regards,
Bruce H. Williams, DVM, DACVP
 
Join the Ferret Health List at
http://groups.yahoo.com/group/Ferret-Health-list
[Posted in FML issue 3396]