Newsgroups: bit.listserv.psycgrad
Date:         Mon, 16 Nov 1992 14:52:36 EST
              <PSYCGRAD@UOTTAWA.BITNET>
From:         Monika Trzcinska <054470@UOTTAWA.BITNET>
Subject: Re: HELP! Anesthesia Info On Rodents Needed!

On Fri, 13 Nov 1992 15:57:00 EDT <KMORGAN@WHEATNMA> said:

>Help!  I've been going around in circles trying to find some
>information on the correct dosage of ketamine to use with rats.
>Specifically, the questions are:
>
>1)  How much ketamine hydrochloride, at what concentration is needed to
>anesthetise an adult female rat?
>
>2)  How best to give this?  IM? IP?
>
>3)  Is Rompun recommended as an addition?  If so, how much at what
>concentration?
>
>4)  If so, how best to give this?  IM?  IP? etc.
>
>5)  Is atropine sulfate recommended to minimize aspiration?  If so, how
>and etc?
>
>6)  Approximate time that animal will be down at this dose.
>
>Thanks!
>
>--Kathy Morgan
>kmorgan@wheatnma.bitnet

Kathy, hope this helps:
Note: These concentrations are for adult MALE rat (around 300 grams)

If the brand of ketamine that you have is KETALAR (50mg/ml) and its
concentration is 100mg/kg, you want to use a dose 30mg/300g rat,
then you would inject 0.6 ml I.M or I.P.
However, if the concentration that you have in 100mg/ml, you would use
half of it, i.e 0.3 ml I.M or I.P.

You also use ROMPUN (XYLAZINE) in combination with ketamine:
Once again if the dosage on the bottle says: 20mg/ml you would use 0.1 ml I.M
If the dosage is 100mg/ml, you would use 0.02 ml I.M

So, for an average rat of 300grams, you would give the following MIXTURE:

0.6 ml of 50mg/ml ketamine + 0.1 ml of 20mg/ml rompun = 0.7 ml of drugs
OR
0.3 ml of 100mg/ml ketamine + 0.02 ml of 100mg/ml rompun = 0.32 ml of drugs

As with any anaesthetic you should inject ATROPINE SULFATE (0.5 mg/ml)
0.25 ml S.C preferably (that is what our animal tech tells us), but
you could also inject it I.M (if you are brave enough to do it on a moving
animal - rats hate it!) or I.P.
Atropine controls excessive bronchial secretions.
Apparently it is difficult to O.D the animal on ketamine.  Although this drug
is used as an anaesthetic it also has "dissociative" properties and may not
be the best drug of choice.  In other words, the animal will not move, but it
may still feel some pain...

Have you considered using somnotol (SODIUM PENTOBARBITAL, 65 mg/ml) as
a better choice?
In our lab, for an 340 grams rat, we would use 0.34 ml of somnotol I.P, in
conjunction with ROMPUN (20mg/ml) 0.05 ml, I.M (once the animal is down).
The animal can stay down for up to 3 hours, or longer.  With ketamine, my
understanding is that its action is shorter (on the average 1 hour).

One warning with somnotol:  Very light animals (below 300grams) may easily
O.D and the heavy animals (above 380grams) may not go down on body weight
injection.  You then have to give supplemental injections of 0.05, or 0.1 ml.
of course risking to O.D the animal...

I guess there is no such thing as a perfect drug!


                                 _
    ) (    Monika Trzcinska    _- o   ) (   054470@ACADVM1.UOTTAWA.CA
   )   (----------------------- o o  )   (----------------------------
    ) (                        -_ o   ) (
                                 -
 "Before we can have applied science, we must have a science to apply"

                                                              D.O.Hebb
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