The development and use of a cage-topper to enhance rat welfare (2025)

Neville, V., Phelon, L., Handley, C. et al.

Abstract

The welfare of rats used in scientific research is an important concern. Recent studies show that larger, more complex housing improves rat welfare compared to standard conventional cages. However there are typically both practical and financial constraints to implementing this. We developed a cage topper that can be added to a standard rat cage to provide additional space and complexity and that can be built in-house at a low cost. Here, we introduce the design of this cage topper and discuss its utility from the perspective of a researcher, a named animal care and welfare officer/lead technician, and a named veterinary surgeon. We concluded that while the cage topper is likely to provide a welfare benefit that more research is needed to assess if there are any adverse effects of the cage topper on animal health and biosecurity. At present the cage topper may be most useful to enhance the welfare of rats who are healthy who would otherwise be housed in non-individually ventilated cages conventional cages.