f6098d8b__and_Use_of_Laboratory_Animals__Comments
[ID] 8 [Entry Date] 02/28/2011 at 05:43:15 PM [Affiliation] Self [Organization Name] National Jewish Health [Organization City and State] Denver, Colorado [Comments] 
Comment 1: The 8th edition of "The Guide" should NOT be adopted for the following reason: On page 57 of "The Guide", Table 3.2 lists recommended minimum cage floor space per mouse. The only change from the 7th edition is that breeding triads are not allowed in standard shoebox (77sq. inches) cages because a single female with a litter should have at least 51 sq. inches of space. The maximum recommended number of adult (>25 g) mice per shoebox cage remains at 5. However, I could find no scientific basis for these recommendations. In fact, the references cited on p. 58 with regard to cage space argue, if anything, that for many strains, more mice can be housed per cage than the minimum currently recommended by the 7th edition (Davidson Comp. Med. 57:355, 2007; Smith et al. Comp. Med. 54:656, 2004; Gonder and Laber ILAR J 48:29, 2007; Smith et al. Comp. Med. 55:368, 2005. One of these shows that C57BL/6 mice, housed at 10 per shoebox cage, are as healthy as those at 5 per cage. Another reference provides evidence of anxiety disorder in mice that are not sufficiently crowed. Therefore, on the basis of the science cited by the authors of "The Guide", I believe that breeding traids should be allowed and that the minimum amount of space per mouse should be doubled over the current space specified by the 7th edition, with the usual footnote that more space may be required for some strains or in special circumstances.
Listing of Public Comments on Proposed Adoption and Implementation of the Eighth Edition of the Guide for the Care and Use of Laboratory Animals