Effects of cage-cleaning frequency and bedding type on laboratory rat health and welfare (2006)

Mason, G. J., Burn, C. C.

Abstract

They were cleaned either twice-weekly, weekly, or every 2 wk and kept on either aspen woodchips or an absorbent paper bedding. Behavioral welfare indicators, injuries and general health, weight gain, chromodacryorrhoea, willingness to be handled and post-mortem lung pathology were all monitored, along with ammonia levels. All 3 experiments suggested that altough it affected ammonia levels, non-aggressive skirmishing, and willingness to be handled, cleaning frequency did not have an important impact on rat welfare. However, rats on aspen chip bedding had higher sneezing rates and lung pathology than those on paper bedding. The results thus raise concerns about the use of aspen chip bedding, which although relatively inert compared with other wood beddings was nevertheless more harmful thant paper bedding.