546" APPENDIX 



preventing recontamination after treatment and during packaging, storage, and 

 transportation. 



Drinking water is frequently overlooked as a means of introducing pathogenic 

 agents. Periodic and frequent examinations of tap water should be made to insure 

 purity or, better still, water may be pasteurized by flash pasteurization of the type 

 used in the industrial processing of milk (161° F. for 15 seconds). 



The introduction of a new stock to a mouse colony always presents a potential 

 threat to the health of the colony. New mice should be received and unpacked in 

 quarters apart from the breeding, holding, and experimental rooms. They should be 

 removed from shipping cartons immediately and examined carefully for physical condi- 

 tion. A carton of arriving animals should be transferred to the same cage when possible. 

 Any carton containing more sick, moribund, or dead animals than usual should be 

 noted and all these animals, including animals apparently well, should be discarded 

 or sent to a diagnostic laboratory. 



Water, food, and clean cages should be made available at once. After being 

 unpacked, transferred, and examined in the receiving room the mice then should be 

 moved to a quarantine room. Here they should be maintained until passing suitable 

 checks on their state of health. A good procedure involves introduction of several 

 mice (at least two mice that are 6-8 weeks old, preferably of the same strain) from 

 the colony or room into which the new mice are to be admitted. These are placed in 

 each cage with new animals and remain for four weeks. At the end of this time (or 

 earlier if any become sick or die) these test mice are bled, killed, and necropsied. 

 Serum samples should be tested for ectromelia (mouse pox) and organs bacteriologically 

 examined for Salmonella sp. and other pathogens. The new mice may be tested 

 upon arrival by sampling of feces for the presence of Salmonella or other enteric patho- 

 gens. If the test animals remain well and pass the laboratory tests (including serum 

 tests for ectromelia) the new animals may be admitted to the animal rooms. It should 

 always be kept in mind that sickness or death of mice recently introduced to an animal 

 room does not imply that these animals brought in a new disease (particularly 

 if illnesses or deaths occur one or two weeks after arrival) . This could be indicative 

 of susceptibility of new animals to diseases already present in the existing group, the 

 latter having carried the agents in latent form. 



FACILITIES AND EQUIPMENT 



Literature dealing with the physical necessities for maintaining a colony of mice 

 or other small animals should be studied thoroughly as the first step in setting up an 

 animal colony. Several agencies for disseminating information of this type have 

 come into existence in this country and in Great Britain. The information provided 

 in this appendix is not intended to supplant other material on this subject, but merely 

 to facilitate the process of establishing and maintaining a colony of mice. 



Probably no two laboratories use exactly the same methods, equipment, and facili- 

 ties to raise mice. A research organization contemplating construction of extensive 



