Part 3.5 Maintenance and hygiene

This is Part 3.5 of the Code of Practice for the Housing and Care of Laboratory Mice, Rats, Guinea Pigs and Rabbits.

Regular cleaning and maintenance and a high level of hygiene are essential for good husbandry and welfare. There is, however, a real danger of over cleaning cages used by pregnant and lactating animals. Such disturbances can result in cannibalism or mismothering. Odour marking is also an important activity in these species, and cleaning disturbances can cause a degree of social disruption.

Minimum standards for maintenance and hygiene:

1. Animal rooms and houses must be kept clean, tidy, vermin-proof and in good repair to facilitate effective cleaning.
2. Bedding in animal enclosures must be changed as often as necessary to keep animals clean, dry and comfortable.

General recommendations:

1. Decisions on frequency of cleaning should be based on cage system, type of animal, stocking densities, and the ability of ventilation systems to maintain suitable air quality. Alternation of partial cleaning (removal and replacement of soiled bedding) with full cleaning, permits some odour cues to remain in the cage and reduces the disturbance to the animals.
2. Care should be taken with the use of bleach and associated fumes, which may lead to disturbances of the young and mismothering.
3. Routines should be established for cleaning, washing, decontaminating or sterilising cages and accessories. The choice of detergents, disinfectants, washing and sterilisation systems should be based on the avoidance of contamination and denaturation of the material of the enclosure. Manufacturers' recommendations should be heeded. SOPs / Checklists should be established within an institution for routine maintenance and cleaning.
4. Any smell of ammonia should be investigated.
5. The movement of personnel between rooms of the animal facility should take into account 'clean' and 'dirty' areas, including the maintenance of differential air pressures where relevant.
6. Climate control systems such as those that regulate ventilation and temperature should undergo regular maintenance. In addition, ventilation filters should be changed as required, and autoclaves and cage washers should be serviced regularly.