The Animal Welfare Act and the Guide for the Care and Use of Animals have established schedules for frequency of cleaning animal rooms and for changing cages. In some cases frequent cage cleaning may be disruptive to research objectives, as in the case of reproductive studies where frequent changes may eliminate pheromones necessary for reproduction. Adding a small portion of bedding from the soiled cage to the fresh cage may prevent such problems while maintaining sanitation. Schedules can be altered to accommodate special research needs with prior approval of the Veterinarian.

Research personnel who are responsible for changing animal cages in the vivarium must obtain blue "Special Instruction" cards from DLAM, indicating the start and end dates of the special husbandry arrangements. In addition, the individual(s) responsible for changing the cages must keep a record in the animal room indicating the dates on which this task is performed as well as the initials of the individual who completed the task.