Thinking outside the lab: can studies of pet rats inform pet and laboratory rat welfare?

Surveys provide a low-cost means to obtain large amounts of data that are ideal for conducting exploratory research, and they are becoming an increasingly valuable tool in a veterinary context. We investigated whether surveys of pet rat owners might provide useful data that could pave the way for more targeted empirical studies of pet and laboratory rat welfare. To achieve this, we used an online survey, distributed via social media, in which we asked pet rat owners questions about the housing, handling, and behaviour of their pet rats, from which we obtained 677 fully-completed surveys. We conducted both qualitative and quantitative analyses of these data, examining the reported frequency of the behaviours and using general linear models to investigate how these reported frequencies varied according to age, sex, total number of rats owned, human-interaction (a variable which summarised data relating to questions about human interaction), total number of enrichment types (a variable which summarised data relating to the provision of enrichment), and predator exposure (a variable which summarised data about the ownership of predator species). The study firstly identified well-established and intuitive findings that supported the validity of this approach, including age-dependent changes in behaviour. The study also identified behaviours that are commonly performed by pet rats, many of which are restricted by standard laboratory cages and may be restricted in poorer pet rat housing. This includes the first scientific report of ‘boggling’ in rats. Additionally, by assessing which behaviours varied according to predator exposure (which is likely to be aversive to rats), the study identified potentially novel, spontaneous behavioural indicators of rat welfare. Specifically, the reported frequency of each of the following behaviours was significantly reduced by greater exposure to predator species: digging (LRT=7.264, FDR-adjusted p-value=0.032), bounding (LRT=8.990, FDR-adjusted p-value=0.015), pinning (LRT=9.242, FDR-adjusted p-value=0.015), and bruxing (LRT=17.780, FDR-adjusted p-value<0.001). We conclude that survey data obtained from pet rat owners may provide useful and fruitful information that can inform both pet and laboratory rat welfare.