Approved by IACUC: 12/15/98
Reapproved: 6/15/11; 3/28/2012
If rodents are disturbed in the immediate post-partum period, some new dams will eat or injure their pups due to the physical disruption of being moved to a new cage. Although necessary to maintain a sanitary environment, movement to a new cage includes the removal of familiar olfactory cues from the environment. Because bedding is changed on a weekly basis and large numbers of cages are changed each day, it is not possible for Institute for Animal Studies (IAS) staff to routinely avoid changing the bedding of all rodent dams which have recently delivered pups. However, if investigator staff identify and tag cages which contain newly born pups, IAS staff will omit changing the cage bottoms in these cages for the first week postpartum.
To avoid having the cage bottom changed, cages must be clearly identified indicating “Do Not Change”. If a cage has not been changed by IAS staff due to this type of notification, it becomes the responsibility of the investigator and his/her staff to see that bedding is changed soon enough that unsanitary conditions or high levels of intra-cage ammonia do not accumulate. If cages are found in an unsanitary condition at any time, even if they are marked with a “Do Not Change”, IAS staff may move the rodents to a clean cage bottom.