Housing Rodents on Wire Flooring
Overview
Proper housing is essential to animal wellbeing, to the quality of research data and to the health and safety of animal personnel. The primary document specifying housing requirements for rodents used in research and testing is the Guide(1). Although the Guide does not mandate a specific housing method for rodents, solid-bottomed caging with bedding is recommended.
Historically, rodents have often been housed on wire flooring, suspended above a collection pan. Such housing enhanced sanitation of the cage by enabling urine and feces to pass through to the collection tray. However, evidence suggests that solid-bottomed caging, with bedding, is preferred by rodents, allows establishment of a favorable micro-environment and may be more humane 2, 3, 4, 5, 6, 7, 8. Solid-bottomed caging, with bedding, is therefore the recommended housing method for rodents at UCI.
Proposals to house rodents on wire mesh flooring must be submitted to the IACUC and include justification as to why standard solid-bottomed caging, with bedding, is not appropriate or contraindicated in the study.
Guidelines for Use of Wire-Bottomed Caging
- Guinea pigs, chinchillas and rats weighing less than 500 grams and/or in residence less than 4 months may be housed on wire flooring.
- Rodents with litters must have solid flooring with bedding.
- Animal care and investigative staff observing clinical signs of discomfort or lesions related to wire flooring must immediately provide solid flooring with bedding.
References
1 National Resource Council. (1996). Guide for the care and use of laboratory animals. National Academy Press, Washington, D.C.
2 Fullerton, P.M. and Gilliatt, R.W. (1967). Pressure neuropathy in the hind foot of the guinea pig. J Neurol. Neurosurg. Psychiat. 30:18-25.
3 Grover-Johnson, N. and Spencer, P.S. (1981). Peripheral nerve abnormalities in aging rats. J Neuropath. Exp. Neurol. 40(2):155-165.
4 Ortman, J.A., Sahenk, Z. and Mendell, J.R. (1983). The experimental production of renaut bodies. J Neurol. Sci. 62:233-241.
5 Blom, H.J.M., Van Tintelen, G., Van Vorstenbosch, C.J.A.H.V., Baumans, V. and Beyen, A.C. (1996). Preferences of mice and rats for types of bedding material. Lab. Animals 30:234-244.
6 Manser, C.E., Elliot, H., Morris, T.H. and Broom, D.M. (1986). The use of novel operant test to determine the strength of preference for flooring in laboratory rats. Lab. Animals 30:1-6.
7 Manser, C.E., Morris, T.H. and Broom, D.M. (1995). An investigation into the effects of solid or grid cage flooring on the welfare of laboratory rats. Lab. Animals 29:353-363.
8 Rock, F.M., Landi, M.S., Hughes, H.C. and Gagnon, R.C. (1997). Effects of caging type and group size on selected physiologic variables in rats. Contemp. Topics in Lab. Anim. Sci., 36(2):69-72.
