Wire-Bottom Caging for Rodents




Solid-bottom caging with bedding must be used for rodents, unless scientific justification for using wire-bottom caging is provided in the animal use protocol.


  • Acceptable primary enclosures for animals must, among other things, allow for the normal physiologic and behavioral needs of the animals, including urination and defecation, maintenance of body temperature, normal movement and postural adjustments, and, where indicated, reproduction(1). Solid-bottom caging with bedding is preferred by rodents, especially for periods of rest(1,2).
  • There may be instances where use of wire-bottom caging is scientifically justified. For example, the short term (a few days or a few weeks) use of wire-bottom caging for nutrition and metabolism experiments in which coprophagy or consumption of bedding would interfere with experimental objectives or add variation sufficient to increase animal numbers.
  • Scientific justification for the use of wire-bottom caging must include monitoring procedures to ensure the animals’ welfare and compliance with the approved protocol.


Exceptions to the use of solid-bottom caging with bedding must be scientifically justified in the IACUC animal use protocol.


Role of the Investigator

Investigators who wish to house rodents in wire-bottom caging must submit a written scientific justification in their IACUC protocol for doing so, and describe monitoring.

Role of the Animal Care Unit

ACP animal care staff observe rodents daily. If they note any abnormality, they contact ACP veterinary staff to assess the animal. ACP veterinary staff, in consultation with the researcher, will determine the proper course of treatment.


  1. Guide for the Care and Use of Laboratory Animals (Guide), NASNRC, 2011.
  2. The Laboratory Rat, 2nd edition, Suckow, Weisbroth, Franklin, Eds. Academic Press, 2006.
  3. Grover-Johnson N, Spencer P. S. (1981) Peripheral nerve abnormalities in aging rats. J Europathol Exp Neurol. 40(2):155-165
  4. Ortman J.A., Sahenk Z, Mendell J. R. (1983). The experimental production of renautbodies. J Neurol Sci. 62(1-3):233-241
  5. Weisbbroth, S.H. (1979) Chemical contamination of lab animals beddings: problems and recommendations. Lab Anim. (8):24-34.

Approved Date

Revised Date