The development of a quantitative and qualitative protocol for assessing the welfare of laboratory mice

Abstract

Mice are the most commonly used species for biomedical research. Maintaining high levels of welfare for these animals is critical for the individual animal and for ensuring the scientific data collected from them is of high quality. An efficient protocol for assessing laboratory mouse welfare should include physiological, psychological and environmental indicators, and should be able to recognise both welfare strengths and shortcomings. The protocols that are currently used often lack indicators which assess the animal’s psychological state, which is necessary for a holistic assessment and critical for animal welfare. This study aimed to develop a holistic protocol for the assessment of laboratory mouse welfare when the assessment is made in an audit or every day. The development of the protocol involved three stages: [1] validity, practicability and reliability assessment of existing indicators, through a Delphi consultation technique, [2] the validation of a novel indicator (Qualitative Behavioural Assessment –QBA) for the assessment of emotional expressions, [3] the reliability and practicability assessment of the developed laboratory mouse welfare protocol. The Delphi consultation identified hunched posture, coat condition, the exhibition of normal and abnormal behaviour and usage of nesting material as the most valid, reliable and practical indicators for welfare assessment in a laboratory environment. The most common handling method for laboratory mice is tail handling, which produces anxiety thus new techniques have been developed for handling laboratory mice such as tube handling. QBA showed a high intra and inter-observer agreement in the assessment of emotional states for laboratory mice that had undergone handling by two different techniques. This study demonstrated that mice handled by their tail were described as "anxious/fearful" whereas mice handled by a tunnel were described as "confident/ playful." The final protocols for an audit and everyday welfare assessment of laboratory mice demonstrated to be practical and reliable between assessors with experience in laboratory mice. These protocols can be used in laboratory facilities for assessing laboratory mice welfare, incorporating psychological state using QBA. The 3-phase method used to construct the final protocol showed to be a comprehensive process which explored well-know and novel indicators and comprises all aspects of mouse laboratory welfare including QBA as a novel method of assessing psychological state. The process of developing a protocol for assessing laboratory mouse welfare is critical and considering experts, previous and novel indicators can improve the assessment quality by including all the components of the definition of welfare.