I am working with C57BL6 mice, which are little aggressive.
I need to feed them by oral gavage. We have tried doing it in wake animals but they are giving us a tough time holding them and even if we manage to do that, the animal is wriggling so much that we ended up injuring one mice while performing the gavage.
So I want to know whether it can be considered to anesthetize the mice and then perform the gavage?
Any references or videos demonstrating the same would be helpful.
Dear Mallu,
Having administered per os treatments in the past (although mostly to rats), I totally agree with Ornella to say that anesthetizing animals before gavage isn't the right solution.
Since your problem seems mainly practical, the link below contains a video that could be of interest to observe how to effectively hold the animal and insert the feeding needle in its mouth, throat and oesophagus.
Rodents sometimes need to get used to the procedure to relax, so do not hesitate to pre-condition them (handling, habituation to the introduction of the feeding needle, possibly a “mock” water injection) a couple of days before injecting your drug. This will reveal extremely useful, especially if you wish to apply chronic treatments in obedient subjects.
Good luck,
David
http://www.jove.com/video/2771/manual-restraint-common-compound-administration-routes-mice
Hello,
I oral gavage mice very frequently but I never anesthetize them, I think it would be even more difficult and then the anestesia could interfere with the drugs/compound/ food if it is a special one, you are gavaging. The risk of suffucating then is much higher, I guess. I ahven't seen anyone doing, but maybe it is possible.
I would suggest you try different tecnique of holding them, and try to put them in a condition they can't move the head. I usually do C57 and even if they are initially a bit unhappy, I never had real problem at the end, the mice get used.
Ornella
I aggree with the viewpoint of Cappellari, I also think it is better to oral gavage mice when they are wake. Maybe it is difficult to do that to rat, in particular when they are adult ones.
Dear Mallu,
Having administered per os treatments in the past (although mostly to rats), I totally agree with Ornella to say that anesthetizing animals before gavage isn't the right solution.
Since your problem seems mainly practical, the link below contains a video that could be of interest to observe how to effectively hold the animal and insert the feeding needle in its mouth, throat and oesophagus.
Rodents sometimes need to get used to the procedure to relax, so do not hesitate to pre-condition them (handling, habituation to the introduction of the feeding needle, possibly a “mock” water injection) a couple of days before injecting your drug. This will reveal extremely useful, especially if you wish to apply chronic treatments in obedient subjects.
Good luck,
David
http://www.jove.com/video/2771/manual-restraint-common-compound-administration-routes-mice
You can, but I strongly advise against anesthesia. Your problem is one of poor technique, not overly squiggly mice. Further, general anesthesia is potentially dangerous to the animal and should not be routinely used as a method of restraint. I suggest getting a skilled person to teach you proper gavage technique. For small volumes you might consider using a gavage needle to put the infusate at the posterior pharynx and totally avoid gavage.
Jerry Silverman
A tip I was given was to dip the end of the oral gavage in something sweet like sucrose solution during the habituation and even the actual experiment if it will not interfere with your study. The mice might actually help you by swallowing the gavage.
Handling is the key aspect to the gavage process.What I teach students is to pin the mouse on the cage top,which I call the"V" approach.Your thumb is positioned at 2 o'clock and your other four fingers are tucked to your palm.Your thumb and first finger are now on either side of its body,so when when you lift up the body you grab alot of the back skin,and if done real well you will see its ears touch each other.Now I describe this hold as if the mouse was in a straight jacket.The mouse now is perfectly still.
Dear friend
As i was read in the most articles it is not recommended to anesthetize them, I think handling is the most important thing for oral gavage (as other friends mentioned it before). before starting oral gavage just practice handling, You can also visit this video:
http://www.procedureswithcare.org.uk/oral-gavage-in-the-mouse/
Good luck
As to my previous answer,it all in the handling.If you gather enough back skin the mouse will be unable to move.As far as the administration of the ball tipped needle,if you hold the syringe like you were throwing a dart and guide the needle over the roof of the mouth you should have no problem. Good luck
I was taught a better way to handle mice,as described in my last answer.The handler has little control of the mouse.
I think the problem is not the mice, but your mouse handling skills. B6 are one of the most commonly used strains in biomedical research and they are not an overly aggressive strain. You may want to try gentle handling, maybe three minutes daily in a cupped hand for about a week before you start the gavage to get them more acclimated to handling. The more acclimated they are to handling, the less problematic they may be. Then I would recommend practice with basic handling and restraint to make sure you have a good ability prior to starting the gavage. Gavage is a tricky technique in general so you need good handling/restraint skill foundation before trying to accomplish the gavages. A lot of institutional veterinary departments offer training on such techniques, or you can even have their technical staff do this for you, so hopefully that is available to you. Anesthesia is not the answer, and would likely cause more issues.
I'm a little late to the thread, but I have never used this method before, and I had the same question about anesthesia. I searched the literature and found the linked article that shows, contrary to all of the other posts on this thread, light isoflurane is advantageous before gavage to reduce stress and other anatomical/physiological complications. The sample size per groups is low, but the experimenter had 2 years prior gavage experience.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5113884/