Laboratory Animal Science is a multidisciplinary, auxiliary science contributing to the humane use and care of laboratory animals and to the quality of animal experimentation. It includes the biology of laboratory animals, their environmental requirements, genetic backgrounds, prevention and treatment of diseases, optimising experimental techniques, reduction of pain and discomfort ( eg anaesthesia and analgesia), possibilities for alternatives to the use of animals and ethical aspects of animal experimentation.
The keywords in this field are the welfare of laboratory animals and connected with that the quality of animal experiments.
Guiding principles are the three R´s of Replacement of living animals by in vitro techniques, computerized models, videos etc, Reduction of the number of animals by using suitable experimental designs, by controlling environmental factors and by standardizing the animal population and Refinement of the experimental procedures and the environmental conditions of the animals, in order to minimize pain and distress and to meet the physiological and behavioural needs of the animals.

Worldwide about 100 million vertebrates per year are used, contributing mostly to the advance of biomedical science and experiencing minor to severe discomfort.
Ca 80 % of the used vertebrates are rats and mice . Ethical problems with animal experimentation has been raised from the public, leading to legislation on the use of laboratory animals in Europe.
The environment of the laboratory animal has a great impact on the laboratory animal, thereby influencing the outcome of experiments. Standardisation of the environment has been seen as a main factor in reducing the number of the animals used and together with economical and ergonomical aspects have led to laboratory animal housing, not meeting the animal`s behavioural and physiological needs, which may result in abnormal behaviour and disease. Environmental enrichment allow the animals to express more of their species specific behaviour, which reduces stress in the animals, thereby making them a more suitable animal model . However, changes in housing conditions often meet reluctance due to several factors, such as variation in experimental results, which may occur, dependent of eg the type of enrichment and the parameter used.