Lifting laboratory rats: A survey of methods, handlers’ reasons and concerns, and rat behavioural responses

Abstract

Lifting mice by the tail is of animal welfare and scientific concern, but rat lifting methods are little researched, potentially differing from mice. Using an online questionnaire we explored different methods for lifting laboratory rats, alongside handlers’ reasons and concerns, and rat behavioural responses. We received 249 valid responses from self-selected rat handlers across research sectors, job roles, and 26 countries (39% UK). In this sample, eight different lifting methods, plus ‘other’, were used; Shoulder saddle (39%), Chest-and-bottom support (20%) and Tail lifting (11%) were most common. Regarding respondents’ reasons for using their main lifting method, those using Tail lifting selected ‘rat comfort’ significantly less frequently, and ‘quick’ more frequently, than did those using other methods. Most respondents had no concerns about their main lifting method, but those using Tail lifting were significantly more concerned about possible ‘stress to the rat’ than were those using Chest-and-bottom support. Concerns about speed, feasibility and scientific validity were rare. Rats reportedly defecated significantly more, and sniffed the hand less, when Tail lifted than when lifted using Chest-and-bottom support. Respondents who used Cupped hands reported rats to approach, sniff and climb onto their hand significantly more than respondents using certain other methods did. Notwithstanding potential sample bias, the findings suggest that lifting rats by the tail risks unnecessary suffering. It is also potentially concerning that the most common method, Shoulder saddle, showed no significant benefits over Tail lifting. Chest-and-bottom support, Cupping, Tunnel, and some rarer methods, may offer more refined methods for lifting rats.