To Bob Raymond (intended for the entire FML):
>Would the ferret surgeons here comment on the desirability of gas
>anesthesia for ferrets as opposed to injectible anesthesia?
 
     Ah - another chance to show how dogmatic I can be!!!   But this is
important enough a topic that I don't mind....
 
    Just as there are practitioners who believe that any vaccine off the
shelf can work as well as any other, or any antibiotic that works for one
disease should work for another, unfortunately there are also practitioners
that believe one anesthetic agent should work for all types of animals in
their practice.  Unfortunately, in ferrets, this is just not so.
 
    The only acceptable type of anesthetic agent for general anesthesia
in the ferret is gas, and preferably a gas anesthetic called isoflurane.
Most vets use it, but other types of gas anesthetics, such as halothane are
still in use.  Isoflurane currently is the safest, with the least chance of
generating a life-threatening cardiac arrhythmia or causing liver disease
9both of which may be seen RARELY with halothane.
 
     But now the real point of this post - many uninformed vets will use
an injectable anesthetic routinely in ferret patients - ketamine - which is
often used in cats for spays and other minor surgery.  The effects of
injectable anesthetics are extremely unpredictable in the ferret, and while
young, healthy ferrets may tolerate it with no problem, older ferrets are at
risk for arrhythmia and cardiovascular shock, which may result in
intraoperative death or failure to wake up post surgically.  'Tis true -
many of us used it ten or fifteen years ago, when little was known about
ferrets except they were "just like cats", but with the newer, safer, gas
anesthetics on the markets, there simply is just no call to use an
injectable anesthetic in an older ferret (or a younger one, in my opinion).
 
    Other problems with injectables - 1) once you give it, you can't get
it back.  You can't lighten anesthesia if the patient gets too deep, which
you can by adjusting the levelof a gas anesthetic being administered to the
patient.  2)  Most injectables are eliminated either by the kidneys, or by
being broken down in the liver.  Patients with renal or liver disease will
be hit harder by these anesthetics, often with disastrous consequences.  Gas
anesthetics are eliminated via the respiratory tract.  Most ferrets, even
with severe disease, will go down quickly with isoflurane, and come up
within 5-10 minutes.  No other premedications are necessary.  With ketamine
or other injectables, ferrets may sleep for hours, and other premedications,
such as atropine are required to control excess salivation and prevent
vomiting, and acepromazine, a tranquilizer, is required to keep the animal
from comng up in a hyperexcited state.
 
     Finally, occasionally ketamine anesthesia in the ferret will result
in seizure activity, which requires administration of Valium to control.
 
    If your ferret is going in for surgery, demand gas (isoflurane)
anesthesia.  You've already greatly increased the chances for a successful
outcome.
 
Back to you, Bob....
 
Bruce Williams, DVM, DACVP
Dept. of Vet Path, AFIP
[log in to unmask]  OR
Chief Pathologist, AccuPath
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[Posted in FML issue 1312]