Weighing in with anecdotes regarding the blood-letting techniques.  I've
seen my (wonderful) vet get blood using both a syringe and a nail clip.
When larger amounts of blood have been needed, such as for a CBC, she's
gone for the syringe/needle method.  When small amounts have been needed,
such as for a quick glucose check or packed cell count, she's gone for
the nail clip.  I have no hesitations having her continue to do the nail
clipping method - it's never seemed particularly painful or stressful.
 
Here's how we've done the nail clip.  I have the ferret facing me, licking
linatone from a dropper.  The vet's on the other side of the exam table,
and she lifts a hind foot and clips a small bit of nail and squeezes
gently - if no blood appears, she clips a small bit more.  When blood does
appear, it's not a gushing spring, it's small drops, which are squeezed
into one of those tiny skinny tubes.  As soon as she has enough, she
applies styptic powder to stop the bleeding.  The ferret is still licking
the linatone, having not noticed a thing.  Once a ferret did notice and
pulled his foot a bit at the moment of the snip, but he didn't make a sound
and didn't stop licking the treat.
 
We also use the linatone trick for vaccinations, and this particular ferret
always whines slightly during the shot, but again, he never stops licking
and doesn't seem terribly concerned.  Anyway, the entire nail clipping
procedure takes *very* little time and seems to be quite non-stressful for
my ferrets.  They've never shown any tenderness on the affected foot and
have certainly not become more difficult to nail trim; in fact, they never
even see the clippers during the blood-taking procedure, because they're
facing me and the work is being done on a hind foot.
 
I should note that the linatone trick is *not* sufficient distraction by
itself for any of my ferrets during temperature-taking (we have to scruff
too), so at least for my guys, getting blood by nail clipping is much less
of an ordeal than the dreaded thermometer. >:-)  Linatone distraction works
so well for my ferrets for so many procedures that whenever I have to leave
them at the vet, a bottle goes along with them.
 
Of course, every situation is unique, and I can only vouch for what I've
seen.  Just wanted to add in my observations to the discussion.
 
Cheers!
-Pam S.
[Posted in FML issue 2924]