Keeping mice in cages - (Aug/05/2008 )

Hey everyone,

Male mice fight and I have 56 of them. They'll be divided into 7 groups of 8. However, I wouldn't want to put all 8 in a cage (the cage wouldn't fit too). How many should go into a cage? Any experience with this?

Thanks.

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We have had up to 5 or so mice in the same cage, and yes they sure did fight!! I would recommend checking with your animal care facility to see what they suggest, as I'm sure it would depend on your mouse strain also. Ours were "wild" mice (colony breed from wild caught mice) and they were MUCH more fiesty than any of the laboratory strains we have worked with.

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Not an expert but should depend on the size of the cage. We keep max 5 in ours (not counting new borns). They fight but not very badly. I think they have one dominant in the pack.

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Housing density guidelines are described in the Guide for the Care and Use of Laboratory Animals (see URL below, specifically Table 2.1). Your IACUC should have this information for you.

http://www.nap.edu/readingroom/books/labrats/contents.html

The guidelines are based on total combined body weight of all animals in the cage, the floor area of the cage, and the height of the cage. As others have indicated, typical denstity for adult mice in cages of typical size is 5 mice/cage.

For our male mice, I will start with 5/cage. Usually there is some fighting at the start (typically not severe) until they work out the hierarchy. Every once in awhile, however, I get a cage in which there is an "idiot" of a mouse who keeps terrorizing the others - sometimes causing very severe wounds. This mouse I will isolate to its own cage. Sometimes just reducing density (splitting the group to 2 in one cage, 3 in the other) and/or adding enrichment works.

Good luck!
SK

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We are only allowed to keep 4 male mice per cage. 5/cage for females.

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This link does not work.

"File not found. We apologize for the inconvenience, but we are unable to locate the content you requested."

This one works...
http://www.nap.edu/readingroom/books/labrats/

Then click on "Complete Listing of the Contents of the Report"

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Sorry about that everyone. When first posted it worked - really.

Just now, I tried the abbreviated URL from Minnie Mouse, but it too did not work - same 404 error message. I'll try to rustle up another source.

Bottom line is that this info is in "The Guide..." - your vivarium administrators and IACUC members should have this and use it as guidance for their own animal care and use regulations.

Good luck!
SK

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Try this to access info in the document:

Go to: www.nap.edu/

Click: Biology and Life Sciences (on left under "Topics")

Click: Lab Animal Research (on left under "Subtopics")

Click: Guide for the Care and Use of Laboratory Animals (it's on the second page of results)

Click: "Read this book onlne, free!" (Upper left)

Hope this works for you.
SK

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Thanks everyone! Thanks Minnie Mouse and SamOH. Thank you bioforum for all the help! I appreciate them all.

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